vendor/github.com/miekg/dns/.gitignore

+*.6
+tags
+test.out
+a.out

vendor/github.com/miekg/dns/CODEOWNERS

+* @miekg @tmthrgd

vendor/github.com/miekg/dns/CONTRIBUTORS

@@ -7,3 +7,4 @@ Marek Majkowski
 Peter van Dijk
 Omri Bahumi
 Alex Sergeyev
+James Hartig

vendor/github.com/miekg/dns/LICENSE

-Extensions of the original work are copyright (c) 2011 Miek Gieben
-
-As this is fork of the official Go code the same license applies:
-
 Copyright (c) 2009 The Go Authors. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -30,3 +26,5 @@ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+As this is fork of the official Go code the same license applies.
+Extensions of the original work are copyright (c) 2011 Miek Gieben

vendor/github.com/miekg/dns/Makefile.fuzz

+# Makefile for fuzzing
+#
+# Use go-fuzz and needs the tools installed.
+# See https://blog.cloudflare.com/dns-parser-meet-go-fuzzer/
+#
+# Installing go-fuzz:
+# $ make -f Makefile.fuzz get
+# Installs:
+# * github.com/dvyukov/go-fuzz/go-fuzz
+# * get github.com/dvyukov/go-fuzz/go-fuzz-build
+
+all: build
+
+.PHONY: build
+build:
+	go-fuzz-build -tags fuzz github.com/miekg/dns
+
+.PHONY: build-newrr
+build-newrr:
+	go-fuzz-build -func FuzzNewRR -tags fuzz github.com/miekg/dns
+
+.PHONY: fuzz
+fuzz:
+	go-fuzz -bin=dns-fuzz.zip -workdir=fuzz
+
+.PHONY: get
+get:
+	go get github.com/dvyukov/go-fuzz/go-fuzz
+	go get github.com/dvyukov/go-fuzz/go-fuzz-build
+
+.PHONY: clean
+clean:
+	rm *-fuzz.zip

vendor/github.com/miekg/dns/Makefile.release

+# Makefile for releasing.
+#
+# The release is controlled from version.go. The version found there is
+# used to tag the git repo, we're not building any artifacts so there is nothing
+# to upload to github.
+#
+# * Up the version in version.go
+# * Run: make -f Makefile.release release
+#   * will *commit* your change with 'Release $VERSION'
+#   * push to github
+#
+
+define GO
+//+build ignore
+
+package main
+
+import (
+	"fmt"
+
+	"github.com/miekg/dns"
+)
+
+func main() {
+	fmt.Println(dns.Version.String())
+}
+endef
+
+$(file > version_release.go,$(GO))
+VERSION:=$(shell go run version_release.go)
+TAG="v$(VERSION)"
+
+all:
+	@echo Use the \'release\' target to start a release $(VERSION)
+	rm -f version_release.go
+
+.PHONY: release
+release: commit push
+	@echo Released $(VERSION)
+	rm -f version_release.go
+
+.PHONY: commit
+commit:
+	@echo Committing release $(VERSION)
+	git commit -am"Release $(VERSION)"
+	git tag $(TAG)
+
+.PHONY: push
+push:
+	@echo Pushing release $(VERSION) to master
+	git push --tags
+	git push

vendor/github.com/miekg/dns/README.md

 [![Build Status](https://travis-ci.org/miekg/dns.svg?branch=master)](https://travis-ci.org/miekg/dns)
+[![Code Coverage](https://img.shields.io/codecov/c/github/miekg/dns/master.svg)](https://codecov.io/github/miekg/dns?branch=master)
+[![Go Report Card](https://goreportcard.com/badge/github.com/miekg/dns)](https://goreportcard.com/report/miekg/dns)
+[![](https://godoc.org/github.com/miekg/dns?status.svg)](https://godoc.org/github.com/miekg/dns)
 
 # Alternative (more granular) approach to a DNS library
 
 > Less is more.
 
-Complete and usable DNS library. All widely used Resource Records are
-supported, including the DNSSEC types. It follows a lean and mean philosophy.
-If there is stuff you should know as a DNS programmer there isn't a convenience
-function for it. Server side and client side programming is supported, i.e. you
+Complete and usable DNS library. All Resource Records are supported, including the DNSSEC types.
+It follows a lean and mean philosophy. If there is stuff you should know as a DNS programmer there
+isn't a convenience function for it. Server side and client side programming is supported, i.e. you
 can build servers and resolvers with it.
 
-If you like this, you may also be interested in:
-
-* https://github.com/miekg/unbound -- Go wrapper for the Unbound resolver.
+We try to keep the "master" branch as sane as possible and at the bleeding edge of standards,
+avoiding breaking changes wherever reasonable. We support the last two versions of Go.
 
 # Goals
 
 * KISS;
 * Fast;
-* Small API, if its easy to code in Go, don't make a function for it.
+* Small API. If it's easy to code in Go, don't make a function for it.
 
 # Users
 
 A not-so-up-to-date-list-that-may-be-actually-current:
 
-* https://cloudflare.com
+* https://github.com/coredns/coredns
 * https://github.com/abh/geodns
+* https://github.com/baidu/bfe
 * http://www.statdns.com/
 * http://www.dnsinspect.com/
 * https://github.com/chuangbo/jianbing-dictionary-dns
@@ -33,51 +35,83 @@ A not-so-up-to-date-list-that-may-be-actually-current:
 * https://github.com/fcambus/rrda
 * https://github.com/kenshinx/godns
 * https://github.com/skynetservices/skydns
+* https://github.com/hashicorp/consul
 * https://github.com/DevelopersPL/godnsagent
 * https://github.com/duedil-ltd/discodns
 * https://github.com/StalkR/dns-reverse-proxy
 * https://github.com/tianon/rawdns
 * https://mesosphere.github.io/mesos-dns/
-* https://pulse.turbobytes.com/
-* https://play.google.com/store/apps/details?id=com.turbobytes.dig
 * https://github.com/fcambus/statzone
 * https://github.com/benschw/dns-clb-go
-* https://github.com/corny/dnscheck for http://public-dns.tk/
+* https://github.com/corny/dnscheck for <http://public-dns.info/>
+* https://github.com/miekg/unbound
+* https://github.com/miekg/exdns
+* https://dnslookup.org
+* https://github.com/looterz/grimd
+* https://github.com/phamhongviet/serf-dns
+* https://github.com/mehrdadrad/mylg
+* https://github.com/bamarni/dockness
+* https://github.com/fffaraz/microdns
+* https://github.com/ipdcode/hades <https://jd.com>
+* https://github.com/StackExchange/dnscontrol/
+* https://www.dnsperf.com/
+* https://dnssectest.net/
+* https://github.com/oif/apex
+* https://github.com/jedisct1/dnscrypt-proxy
+* https://github.com/jedisct1/rpdns
+* https://github.com/xor-gate/sshfp
+* https://github.com/rs/dnstrace
+* https://blitiri.com.ar/p/dnss ([github mirror](https://github.com/albertito/dnss))
+* https://render.com
+* https://github.com/peterzen/goresolver
+* https://github.com/folbricht/routedns
+* https://domainr.com/
+* https://zonedb.org/
+* https://router7.org/
+* https://github.com/fortio/dnsping
+* https://github.com/Luzilla/dnsbl_exporter
+* https://github.com/bodgit/tsig
+* https://github.com/v2fly/v2ray-core (test only)
+* https://kuma.io/
+* https://www.misaka.io/services/dns
+* https://ping.sx/dig
+* https://fleetdeck.io/
+* https://github.com/markdingo/autoreverse
+
 
 Send pull request if you want to be listed here.
 
 # Features
 
-* UDP/TCP queries, IPv4 and IPv6;
-* RFC 1035 zone file parsing ($INCLUDE, $ORIGIN, $TTL and $GENERATE (for all record types) are supported;
-* Fast:
-    * Reply speed around ~ 80K qps (faster hardware results in more qps);
-    * Parsing RRs ~ 100K RR/s, that's 5M records in about 50 seconds;
-* Server side programming (mimicking the net/http package);
-* Client side programming;
-* DNSSEC: signing, validating and key generation for DSA, RSA and ECDSA;
-* EDNS0, NSID;
-* AXFR/IXFR;
-* TSIG, SIG(0);
-* DNS name compression;
-* Depends only on the standard library.
+* UDP/TCP queries, IPv4 and IPv6
+* RFC 1035 zone file parsing ($INCLUDE, $ORIGIN, $TTL and $GENERATE (for all record types) are supported
+* Fast
+* Server side programming (mimicking the net/http package)
+* Client side programming
+* DNSSEC: signing, validating and key generation for DSA, RSA, ECDSA and Ed25519
+* EDNS0, NSID, Cookies
+* AXFR/IXFR
+* TSIG, SIG(0)
+* DNS over TLS (DoT): encrypted connection between client and server over TCP
+* DNS name compression
 
 Have fun!
 
 Miek Gieben  -  2010-2012  -  <miek@miek.nl>
+DNS Authors 2012-
 
 # Building
 
-Building is done with the `go` tool. If you have setup your GOPATH
-correctly, the following should work:
+This library uses Go modules and uses semantic versioning. Building is done with the `go` tool, so
+the following should work:
 
     go get github.com/miekg/dns
     go build github.com/miekg/dns
 
 ## Examples
 
-A short "how to use the API" is at the beginning of doc.go (this also will show
-when you call `godoc github.com/miekg/dns`).
+A short "how to use the API" is at the beginning of doc.go (this also will show when you call `godoc
+github.com/miekg/dns`).
 
 Example programs can be found in the `github.com/miekg/exdns` repository.
 
@@ -101,11 +135,11 @@ Example programs can be found in the `github.com/miekg/exdns` repository.
 * 2915 - NAPTR record
 * 2929 - DNS IANA Considerations
 * 3110 - RSASHA1 DNS keys
+* 3123 - APL record
 * 3225 - DO bit (DNSSEC OK)
 * 340{1,2,3} - NAPTR record
 * 3445 - Limiting the scope of (DNS)KEY
 * 3597 - Unknown RRs
-* 4025 - IPSECKEY
 * 403{3,4,5} - DNSSEC + validation functions
 * 4255 - SSHFP record
 * 4343 - Case insensitivity
@@ -124,26 +158,29 @@ Example programs can be found in the `github.com/miekg/exdns` repository.
 * 6605 - ECDSA
 * 6725 - IANA Registry Update
 * 6742 - ILNP DNS
+* 6840 - Clarifications and Implementation Notes for DNS Security
 * 6844 - CAA record
 * 6891 - EDNS0 update
 * 6895 - DNS IANA considerations
+* 6944 - DNSSEC DNSKEY Algorithm Status
 * 6975 - Algorithm Understanding in DNSSEC
 * 7043 - EUI48/EUI64 records
 * 7314 - DNS (EDNS) EXPIRE Option
+* 7477 - CSYNC RR
+* 7828 - edns-tcp-keepalive EDNS0 Option
 * 7553 - URI record
-* xxxx - EDNS0 DNS Update Lease (draft)
-
-## Loosely based upon
-
-* `ldns`
-* `NSD`
-* `Net::DNS`
-* `GRONG`
-
-## TODO
-
-* privatekey.Precompute() when signing?
-* Last remaining RRs: APL, ATMA, A6, NSAP and NXT.
-* Missing in parsing: ISDN, UNSPEC, NSAP and ATMA.
-* NSEC(3) cover/match/closest enclose.
-* Replies with TC bit are not parsed to the end.
+* 7858 - DNS over TLS: Initiation and Performance Considerations
+* 7871 - EDNS0 Client Subnet
+* 7873 - Domain Name System (DNS) Cookies
+* 8080 - EdDSA for DNSSEC
+* 8499 - DNS Terminology
+* 8659 - DNS Certification Authority Authorization (CAA) Resource Record
+* 8914 - Extended DNS Errors
+* 8976 - Message Digest for DNS Zones (ZONEMD RR)
+
+## Loosely Based Upon
+
+* ldns - <https://nlnetlabs.nl/projects/ldns/about/>
+* NSD - <https://nlnetlabs.nl/projects/nsd/about/>
+* Net::DNS - <http://www.net-dns.org/>
+* GRONG - <https://github.com/bortzmeyer/grong>

vendor/github.com/miekg/dns/acceptfunc.go

+package dns
+
+// MsgAcceptFunc is used early in the server code to accept or reject a message with RcodeFormatError.
+// It returns a MsgAcceptAction to indicate what should happen with the message.
+type MsgAcceptFunc func(dh Header) MsgAcceptAction
+
+// DefaultMsgAcceptFunc checks the request and will reject if:
+//
+// * isn't a request (don't respond in that case)
+//
+// * opcode isn't OpcodeQuery or OpcodeNotify
+//
+// * Zero bit isn't zero
+//
+// * does not have exactly 1 question in the question section
+//
+// * has more than 1 RR in the Answer section
+//
+// * has more than 0 RRs in the Authority section
+//
+// * has more than 2 RRs in the Additional section
+//
+var DefaultMsgAcceptFunc MsgAcceptFunc = defaultMsgAcceptFunc
+
+// MsgAcceptAction represents the action to be taken.
+type MsgAcceptAction int
+
+// Allowed returned values from a MsgAcceptFunc.
+const (
+	MsgAccept               MsgAcceptAction = iota // Accept the message
+	MsgReject                                      // Reject the message with a RcodeFormatError
+	MsgIgnore                                      // Ignore the error and send nothing back.
+	MsgRejectNotImplemented                        // Reject the message with a RcodeNotImplemented
+)
+
+func defaultMsgAcceptFunc(dh Header) MsgAcceptAction {
+	if isResponse := dh.Bits&_QR != 0; isResponse {
+		return MsgIgnore
+	}
+
+	// Don't allow dynamic updates, because then the sections can contain a whole bunch of RRs.
+	opcode := int(dh.Bits>>11) & 0xF
+	if opcode != OpcodeQuery && opcode != OpcodeNotify {
+		return MsgRejectNotImplemented
+	}
+
+	if dh.Qdcount != 1 {
+		return MsgReject
+	}
+	// NOTIFY requests can have a SOA in the ANSWER section. See RFC 1996 Section 3.7 and 3.11.
+	if dh.Ancount > 1 {
+		return MsgReject
+	}
+	// IXFR request could have one SOA RR in the NS section. See RFC 1995, section 3.
+	if dh.Nscount > 1 {
+		return MsgReject
+	}
+	if dh.Arcount > 2 {
+		return MsgReject
+	}
+	return MsgAccept
+}

vendor/github.com/miekg/dns/client.go

@@ -3,132 +3,83 @@ package dns
 // A client implementation.
 
 import (
-	"bytes"
+	"context"
+	"crypto/tls"
+	"encoding/binary"
+	"fmt"
 	"io"
 	"net"
+	"strings"
 	"time"
 )
 
-const dnsTimeout time.Duration = 2 * time.Second
-const tcpIdleTimeout time.Duration = 8 * time.Second
+const (
+	dnsTimeout     time.Duration = 2 * time.Second
+	tcpIdleTimeout time.Duration = 8 * time.Second
+)
+
+func isPacketConn(c net.Conn) bool {
+	if _, ok := c.(net.PacketConn); !ok {
+		return false
+	}
+
+	if ua, ok := c.LocalAddr().(*net.UnixAddr); ok {
+		return ua.Net == "unixgram" || ua.Net == "unixpacket"
+	}
+
+	return true
+}
 
 // A Conn represents a connection to a DNS server.
 type Conn struct {
 	net.Conn                         // a net.Conn holding the connection
 	UDPSize        uint16            // minimum receive buffer for UDP messages
-	TsigSecret     map[string]string // secret(s) for Tsig map[<zonename>]<base64 secret>, zonename must be fully qualified
-	rtt            time.Duration
-	t              time.Time
+	TsigSecret     map[string]string // secret(s) for Tsig map[<zonename>]<base64 secret>, zonename must be in canonical form (lowercase, fqdn, see RFC 4034 Section 6.2)
+	TsigProvider   TsigProvider      // An implementation of the TsigProvider interface. If defined it replaces TsigSecret and is used for all TSIG operations.
 	tsigRequestMAC string
 }
 
+func (co *Conn) tsigProvider() TsigProvider {
+	if co.TsigProvider != nil {
+		return co.TsigProvider
+	}
+	// tsigSecretProvider will return ErrSecret if co.TsigSecret is nil.
+	return tsigSecretProvider(co.TsigSecret)
+}
+
 // A Client defines parameters for a DNS client.
 type Client struct {
-	Net            string            // if "tcp" a TCP query will be initiated, otherwise an UDP one (default is "" for UDP)
-	UDPSize        uint16            // minimum receive buffer for UDP messages
-	DialTimeout    time.Duration     // net.DialTimeout, defaults to 2 seconds
-	ReadTimeout    time.Duration     // net.Conn.SetReadTimeout value for connections, defaults to 2 seconds
-	WriteTimeout   time.Duration     // net.Conn.SetWriteTimeout value for connections, defaults to 2 seconds
-	TsigSecret     map[string]string // secret(s) for Tsig map[<zonename>]<base64 secret>, zonename must be fully qualified
+	Net       string      // if "tcp" or "tcp-tls" (DNS over TLS) a TCP query will be initiated, otherwise an UDP one (default is "" for UDP)
+	UDPSize   uint16      // minimum receive buffer for UDP messages
+	TLSConfig *tls.Config // TLS connection configuration
+	Dialer    *net.Dialer // a net.Dialer used to set local address, timeouts and more
+	// Timeout is a cumulative timeout for dial, write and read, defaults to 0 (disabled) - overrides DialTimeout, ReadTimeout,
+	// WriteTimeout when non-zero. Can be overridden with net.Dialer.Timeout (see Client.ExchangeWithDialer and
+	// Client.Dialer) or context.Context.Deadline (see ExchangeContext)
+	Timeout        time.Duration
+	DialTimeout    time.Duration     // net.DialTimeout, defaults to 2 seconds, or net.Dialer.Timeout if expiring earlier - overridden by Timeout when that value is non-zero
+	ReadTimeout    time.Duration     // net.Conn.SetReadTimeout value for connections, defaults to 2 seconds - overridden by Timeout when that value is non-zero
+	WriteTimeout   time.Duration     // net.Conn.SetWriteTimeout value for connections, defaults to 2 seconds - overridden by Timeout when that value is non-zero
+	TsigSecret     map[string]string // secret(s) for Tsig map[<zonename>]<base64 secret>, zonename must be in canonical form (lowercase, fqdn, see RFC 4034 Section 6.2)
+	TsigProvider   TsigProvider      // An implementation of the TsigProvider interface. If defined it replaces TsigSecret and is used for all TSIG operations.
 	SingleInflight bool              // if true suppress multiple outstanding queries for the same Qname, Qtype and Qclass
 	group          singleflight
 }
 
 // Exchange performs a synchronous UDP query. It sends the message m to the address
-// contained in a and waits for an reply. Exchange does not retry a failed query, nor
+// contained in a and waits for a reply. Exchange does not retry a failed query, nor
 // will it fall back to TCP in case of truncation.
-// If you need to send a DNS message on an already existing connection, you can use the
-// following:
-//
-//	co := &dns.Conn{Conn: c} // c is your net.Conn
-//	co.WriteMsg(m)
-//	in, err := co.ReadMsg()
-//	co.Close()
-//
+// See client.Exchange for more information on setting larger buffer sizes.
 func Exchange(m *Msg, a string) (r *Msg, err error) {
-	var co *Conn
-	co, err = DialTimeout("udp", a, dnsTimeout)
-	if err != nil {
-		return nil, err
-	}
-
-	defer co.Close()
-	co.SetReadDeadline(time.Now().Add(dnsTimeout))
-	co.SetWriteDeadline(time.Now().Add(dnsTimeout))
-
-	opt := m.IsEdns0()
-	// If EDNS0 is used use that for size.
-	if opt != nil && opt.UDPSize() >= MinMsgSize {
-		co.UDPSize = opt.UDPSize()
-	}
-
-	if err = co.WriteMsg(m); err != nil {
-		return nil, err
-	}
-	r, err = co.ReadMsg()
-	if err == nil && r.Id != m.Id {
-		err = ErrId
-	}
-	return r, err
-}
-
-// ExchangeConn performs a synchronous query. It sends the message m via the connection
-// c and waits for a reply. The connection c is not closed by ExchangeConn.
-// This function is going away, but can easily be mimicked:
-//
-//	co := &dns.Conn{Conn: c} // c is your net.Conn
-//	co.WriteMsg(m)
-//	in, _  := co.ReadMsg()
-//	co.Close()
-//
-func ExchangeConn(c net.Conn, m *Msg) (r *Msg, err error) {
-	println("dns: this function is deprecated")
-	co := new(Conn)
-	co.Conn = c
-	if err = co.WriteMsg(m); err != nil {
-		return nil, err
-	}
-	r, err = co.ReadMsg()
-	if err == nil && r.Id != m.Id {
-		err = ErrId
-	}
+	client := Client{Net: "udp"}
+	r, _, err = client.Exchange(m, a)
 	return r, err
 }
 
-// Exchange performs an synchronous query. It sends the message m to the address
-// contained in a and waits for an reply. Basic use pattern with a *dns.Client:
-//
-//	c := new(dns.Client)
-//	in, rtt, err := c.Exchange(message, "127.0.0.1:53")
-//
-// Exchange does not retry a failed query, nor will it fall back to TCP in
-// case of truncation.
-func (c *Client) Exchange(m *Msg, a string) (r *Msg, rtt time.Duration, err error) {
-	if !c.SingleInflight {
-		return c.exchange(m, a)
-	}
-	// This adds a bunch of garbage, TODO(miek).
-	t := "nop"
-	if t1, ok := TypeToString[m.Question[0].Qtype]; ok {
-		t = t1
-	}
-	cl := "nop"
-	if cl1, ok := ClassToString[m.Question[0].Qclass]; ok {
-		cl = cl1
-	}
-	r, rtt, err, shared := c.group.Do(m.Question[0].Name+t+cl, func() (*Msg, time.Duration, error) {
-		return c.exchange(m, a)
-	})
-	if err != nil {
-		return r, rtt, err
-	}
-	if shared {
-		return r.Copy(), rtt, nil
-	}
-	return r, rtt, nil
-}
-
 func (c *Client) dialTimeout() time.Duration {
+	if c.Timeout != 0 {
+		return c.Timeout
+	}
 	if c.DialTimeout != 0 {
 		return c.DialTimeout
 	}
@@ -149,18 +100,116 @@ func (c *Client) writeTimeout() time.Duration {
 	return dnsTimeout
 }
 
-func (c *Client) exchange(m *Msg, a string) (r *Msg, rtt time.Duration, err error) {
-	var co *Conn
-	if c.Net == "" {
-		co, err = DialTimeout("udp", a, c.dialTimeout())
+// Dial connects to the address on the named network.
+func (c *Client) Dial(address string) (conn *Conn, err error) {
+	return c.DialContext(context.Background(), address)
+}
+
+// DialContext connects to the address on the named network, with a context.Context.
+// For TLS over TCP (DoT) the context isn't used yet. This will be enabled when Go 1.18 is released.
+func (c *Client) DialContext(ctx context.Context, address string) (conn *Conn, err error) {
+	// create a new dialer with the appropriate timeout
+	var d net.Dialer
+	if c.Dialer == nil {
+		d = net.Dialer{Timeout: c.getTimeoutForRequest(c.dialTimeout())}
+	} else {
+		d = *c.Dialer
+	}
+
+	network := c.Net
+	if network == "" {
+		network = "udp"
+	}
+
+	useTLS := strings.HasPrefix(network, "tcp") && strings.HasSuffix(network, "-tls")
+
+	conn = new(Conn)
+	if useTLS {
+		network = strings.TrimSuffix(network, "-tls")
+
+		// TODO(miekg): Enable after Go 1.18 is released, to be able to support two prev. releases.
+		/*
+			tlsDialer := tls.Dialer{
+				NetDialer: &d,
+				Config:    c.TLSConfig,
+			}
+			conn.Conn, err = tlsDialer.DialContext(ctx, network, address)
+		*/
+		conn.Conn, err = tls.DialWithDialer(&d, network, address, c.TLSConfig)
 	} else {
-		co, err = DialTimeout(c.Net, a, c.dialTimeout())
+		conn.Conn, err = d.DialContext(ctx, network, address)
 	}
+	if err != nil {
+		return nil, err
+	}
+	conn.UDPSize = c.UDPSize
+	return conn, nil
+}
+
+// Exchange performs a synchronous query. It sends the message m to the address
+// contained in a and waits for a reply. Basic use pattern with a *dns.Client:
+//
+//	c := new(dns.Client)
+//	in, rtt, err := c.Exchange(message, "127.0.0.1:53")
+//
+// Exchange does not retry a failed query, nor will it fall back to TCP in
+// case of truncation.
+// It is up to the caller to create a message that allows for larger responses to be
+// returned. Specifically this means adding an EDNS0 OPT RR that will advertise a larger
+// buffer, see SetEdns0. Messages without an OPT RR will fallback to the historic limit
+// of 512 bytes
+// To specify a local address or a timeout, the caller has to set the `Client.Dialer`
+// attribute appropriately
+func (c *Client) Exchange(m *Msg, address string) (r *Msg, rtt time.Duration, err error) {
+	co, err := c.Dial(address)
+
 	if err != nil {
 		return nil, 0, err
 	}
 	defer co.Close()
+	return c.ExchangeWithConn(m, co)
+}
+
+// ExchangeWithConn has the same behavior as Exchange, just with a predetermined connection
+// that will be used instead of creating a new one.
+// Usage pattern with a *dns.Client:
+//
+//	c := new(dns.Client)
+//	// connection management logic goes here
+//
+//	conn := c.Dial(address)
+//	in, rtt, err := c.ExchangeWithConn(message, conn)
+//
+// This allows users of the library to implement their own connection management,
+// as opposed to Exchange, which will always use new connections and incur the added overhead
+// that entails when using "tcp" and especially "tcp-tls" clients.
+//
+// When the singleflight is set for this client the context is _not_ forwarded to the (shared) exchange, to
+// prevent one cancelation from canceling all outstanding requests.
+func (c *Client) ExchangeWithConn(m *Msg, conn *Conn) (r *Msg, rtt time.Duration, err error) {
+	return c.exchangeWithConnContext(context.Background(), m, conn)
+}
 
+func (c *Client) exchangeWithConnContext(ctx context.Context, m *Msg, conn *Conn) (r *Msg, rtt time.Duration, err error) {
+	if !c.SingleInflight {
+		return c.exchangeContext(ctx, m, conn)
+	}
+
+	q := m.Question[0]
+	key := fmt.Sprintf("%s:%d:%d", q.Name, q.Qtype, q.Qclass)
+	r, rtt, err, shared := c.group.Do(key, func() (*Msg, time.Duration, error) {
+		// When we're doing singleflight we don't want one context cancelation, cancel _all_ outstanding queries.
+		// Hence we ignore the context and use Background().
+		return c.exchangeContext(context.Background(), m, conn)
+	})
+	if r != nil && shared {
+		r = r.Copy()
+	}
+
+	return r, rtt, err
+}
+
+func (c *Client) exchangeContext(ctx context.Context, m *Msg, co *Conn) (r *Msg, rtt time.Duration, err error) {
 	opt := m.IsEdns0()
 	// If EDNS0 is used use that for size.
 	if opt != nil && opt.UDPSize() >= MinMsgSize {
@@ -171,23 +220,51 @@ func (c *Client) exchange(m *Msg, a string) (r *Msg, rtt time.Duration, err erro
 		co.UDPSize = c.UDPSize
 	}
 
-	co.SetReadDeadline(time.Now().Add(c.readTimeout()))
-	co.SetWriteDeadline(time.Now().Add(c.writeTimeout()))
+	// write with the appropriate write timeout
+	t := time.Now()
+	writeDeadline := t.Add(c.getTimeoutForRequest(c.writeTimeout()))
+	readDeadline := t.Add(c.getTimeoutForRequest(c.readTimeout()))
+	if deadline, ok := ctx.Deadline(); ok {
+		if deadline.Before(writeDeadline) {
+			writeDeadline = deadline
+		}
+		if deadline.Before(readDeadline) {
+			readDeadline = deadline
+		}
+	}
+	co.SetWriteDeadline(writeDeadline)
+	co.SetReadDeadline(readDeadline)
+
+	co.TsigSecret, co.TsigProvider = c.TsigSecret, c.TsigProvider
 
-	co.TsigSecret = c.TsigSecret
 	if err = co.WriteMsg(m); err != nil {
 		return nil, 0, err
 	}
-	r, err = co.ReadMsg()
-	if err == nil && r.Id != m.Id {
-		err = ErrId
+
+	if isPacketConn(co.Conn) {
+		for {
+			r, err = co.ReadMsg()
+			// Ignore replies with mismatched IDs because they might be
+			// responses to earlier queries that timed out.
+			if err != nil || r.Id == m.Id {
+				break
+			}
+		}
+	} else {
+		r, err = co.ReadMsg()
+		if err == nil && r.Id != m.Id {
+			err = ErrId
+		}
 	}
-	return r, co.rtt, err
+	rtt = time.Since(t)
+	return r, rtt, err
 }
 
 // ReadMsg reads a message from the connection co.
-// If the received message contains a TSIG record the transaction
-// signature is verified.
+// If the received message contains a TSIG record the transaction signature
+// is verified. This method always tries to return the message, however if an
+// error is returned there are no guarantees that the returned message is a
+// valid representation of the packet read.
 func (co *Conn) ReadMsg() (*Msg, error) {
 	p, err := co.ReadMsgHeader(nil)
 	if err != nil {
@@ -196,14 +273,14 @@ func (co *Conn) ReadMsg() (*Msg, error) {
 
 	m := new(Msg)
 	if err := m.Unpack(p); err != nil {
-		return nil, err
+		// If an error was returned, we still want to allow the user to use
+		// the message, but naively they can just check err if they don't want
+		// to use an erroneous message
+		return m, err
 	}
 	if t := m.IsTsig(); t != nil {
-		if _, ok := co.TsigSecret[t.Hdr.Name]; !ok {
-			return m, ErrSecret
-		}
 		// Need to work on the original message p, as that was used to calculate the tsig.
-		err = TsigVerify(p, co.TsigSecret[t.Hdr.Name], co.tsigRequestMAC, false)
+		err = TsigVerifyWithProvider(p, co.tsigProvider(), co.tsigRequestMAC, false)
 	}
 	return m, err
 }
@@ -218,21 +295,21 @@ func (co *Conn) ReadMsgHeader(hdr *Header) ([]byte, error) {
 		err error
 	)
 
-	if t, ok := co.Conn.(*net.TCPConn); ok {
-		// First two bytes specify the length of the entire message.
-		l, err := tcpMsgLen(t)
-		if err != nil {
-			return nil, err
-		}
-		p = make([]byte, l)
-		n, err = tcpRead(t, p)
-	} else {
+	if isPacketConn(co.Conn) {
 		if co.UDPSize > MinMsgSize {
 			p = make([]byte, co.UDPSize)
 		} else {
 			p = make([]byte, MinMsgSize)
 		}
 		n, err = co.Read(p)
+	} else {
+		var length uint16
+		if err := binary.Read(co.Conn, binary.BigEndian, &length); err != nil {
+			return nil, err
+		}
+
+		p = make([]byte, length)
+		n, err = io.ReadFull(co.Conn, p)
 	}
 
 	if err != nil {
@@ -243,118 +320,87 @@ func (co *Conn) ReadMsgHeader(hdr *Header) ([]byte, error) {
 
 	p = p[:n]
 	if hdr != nil {
-		if _, err = UnpackStruct(hdr, p, 0); err != nil {
+		dh, _, err := unpackMsgHdr(p, 0)
+		if err != nil {
 			return nil, err
 		}
+		*hdr = dh
 	}
 	return p, err
 }
 
-// tcpMsgLen is a helper func to read first two bytes of stream as uint16 packet length.
-func tcpMsgLen(t *net.TCPConn) (int, error) {
-	p := []byte{0, 0}
-	n, err := t.Read(p)
-	if err != nil {
-		return 0, err
-	}
-	if n != 2 {
-		return 0, ErrShortRead
-	}
-	l, _ := unpackUint16(p, 0)
-	if l == 0 {
-		return 0, ErrShortRead
-	}
-	return int(l), nil
-}
-
-// tcpRead calls TCPConn.Read enough times to fill allocated buffer.
-func tcpRead(t *net.TCPConn, p []byte) (int, error) {
-	n, err := t.Read(p)
-	if err != nil {
-		return n, err
-	}
-	for n < len(p) {
-		j, err := t.Read(p[n:])
-		if err != nil {
-			return n, err
-		}
-		n += j
-	}
-	return n, err
-}
-
 // Read implements the net.Conn read method.
 func (co *Conn) Read(p []byte) (n int, err error) {
 	if co.Conn == nil {
 		return 0, ErrConnEmpty
 	}
-	if len(p) < 2 {
-		return 0, io.ErrShortBuffer
+
+	if isPacketConn(co.Conn) {
+		// UDP connection
+		return co.Conn.Read(p)
 	}
-	if t, ok := co.Conn.(*net.TCPConn); ok {
-		l, err := tcpMsgLen(t)
-		if err != nil {
-			return 0, err
-		}
-		if l > len(p) {
-			return int(l), io.ErrShortBuffer
-		}
-		return tcpRead(t, p[:l])
+
+	var length uint16
+	if err := binary.Read(co.Conn, binary.BigEndian, &length); err != nil {
+		return 0, err
 	}
-	// UDP connection
-	n, err = co.Conn.Read(p)
-	if err != nil {
-		return n, err
+	if int(length) > len(p) {
+		return 0, io.ErrShortBuffer
 	}
 
-	co.rtt = time.Since(co.t)
-	return n, err
+	return io.ReadFull(co.Conn, p[:length])
 }
 
-// WriteMsg sends a message throught the connection co.
+// WriteMsg sends a message through the connection co.
 // If the message m contains a TSIG record the transaction
 // signature is calculated.
 func (co *Conn) WriteMsg(m *Msg) (err error) {
 	var out []byte
 	if t := m.IsTsig(); t != nil {
-		mac := ""
-		if _, ok := co.TsigSecret[t.Hdr.Name]; !ok {
-			return ErrSecret
-		}
-		out, mac, err = TsigGenerate(m, co.TsigSecret[t.Hdr.Name], co.tsigRequestMAC, false)
-		// Set for the next read, allthough only used in zone transfers
-		co.tsigRequestMAC = mac
+		// Set tsigRequestMAC for the next read, although only used in zone transfers.
+		out, co.tsigRequestMAC, err = TsigGenerateWithProvider(m, co.tsigProvider(), co.tsigRequestMAC, false)
 	} else {
 		out, err = m.Pack()
 	}
 	if err != nil {
 		return err
 	}
-	co.t = time.Now()
-	if _, err = co.Write(out); err != nil {
-		return err
-	}
-	return nil
+	_, err = co.Write(out)
+	return err
 }
 
 // Write implements the net.Conn Write method.
-func (co *Conn) Write(p []byte) (n int, err error) {
-	if t, ok := co.Conn.(*net.TCPConn); ok {
-		lp := len(p)
-		if lp < 2 {
-			return 0, io.ErrShortBuffer
-		}
-		if lp > MaxMsgSize {
-			return 0, &Error{err: "message too large"}
+func (co *Conn) Write(p []byte) (int, error) {
+	if len(p) > MaxMsgSize {
+		return 0, &Error{err: "message too large"}
+	}
+
+	if isPacketConn(co.Conn) {
+		return co.Conn.Write(p)
+	}
+
+	msg := make([]byte, 2+len(p))
+	binary.BigEndian.PutUint16(msg, uint16(len(p)))
+	copy(msg[2:], p)
+	return co.Conn.Write(msg)
+}
+
+// Return the appropriate timeout for a specific request
+func (c *Client) getTimeoutForRequest(timeout time.Duration) time.Duration {
+	var requestTimeout time.Duration
+	if c.Timeout != 0 {
+		requestTimeout = c.Timeout
+	} else {
+		requestTimeout = timeout
+	}
+	// net.Dialer.Timeout has priority if smaller than the timeouts computed so
+	// far
+	if c.Dialer != nil && c.Dialer.Timeout != 0 {
+		if c.Dialer.Timeout < requestTimeout {
+			requestTimeout = c.Dialer.Timeout
 		}
-		l := make([]byte, 2, lp+2)
-		l[0], l[1] = packUint16(uint16(lp))
-		p = append(l, p...)
-		n, err := io.Copy(t, bytes.NewReader(p))
-		return int(n), err
-	}
-	n, err = co.Conn.(*net.UDPConn).Write(p)
-	return n, err
+	}
+	return requestTimeout
 }
 
 // Dial connects to the address on the named network.
@@ -367,12 +413,72 @@ func Dial(network, address string) (conn *Conn, err error) {
 	return conn, nil
 }
 
+// ExchangeContext performs a synchronous UDP query, like Exchange. It
+// additionally obeys deadlines from the passed Context.
+func ExchangeContext(ctx context.Context, m *Msg, a string) (r *Msg, err error) {
+	client := Client{Net: "udp"}
+	r, _, err = client.ExchangeContext(ctx, m, a)
+	// ignoring rtt to leave the original ExchangeContext API unchanged, but
+	// this function will go away
+	return r, err
+}
+
+// ExchangeConn performs a synchronous query. It sends the message m via the connection
+// c and waits for a reply. The connection c is not closed by ExchangeConn.
+// Deprecated: This function is going away, but can easily be mimicked:
+//
+//	co := &dns.Conn{Conn: c} // c is your net.Conn
+//	co.WriteMsg(m)
+//	in, _  := co.ReadMsg()
+//	co.Close()
+//
+func ExchangeConn(c net.Conn, m *Msg) (r *Msg, err error) {
+	println("dns: ExchangeConn: this function is deprecated")
+	co := new(Conn)
+	co.Conn = c
+	if err = co.WriteMsg(m); err != nil {
+		return nil, err
+	}
+	r, err = co.ReadMsg()
+	if err == nil && r.Id != m.Id {
+		err = ErrId
+	}
+	return r, err
+}
+
 // DialTimeout acts like Dial but takes a timeout.
 func DialTimeout(network, address string, timeout time.Duration) (conn *Conn, err error) {
-	conn = new(Conn)
-	conn.Conn, err = net.DialTimeout(network, address, timeout)
+	client := Client{Net: network, Dialer: &net.Dialer{Timeout: timeout}}
+	return client.Dial(address)
+}
+
+// DialWithTLS connects to the address on the named network with TLS.
+func DialWithTLS(network, address string, tlsConfig *tls.Config) (conn *Conn, err error) {
+	if !strings.HasSuffix(network, "-tls") {
+		network += "-tls"
+	}
+	client := Client{Net: network, TLSConfig: tlsConfig}
+	return client.Dial(address)
+}
+
+// DialTimeoutWithTLS acts like DialWithTLS but takes a timeout.
+func DialTimeoutWithTLS(network, address string, tlsConfig *tls.Config, timeout time.Duration) (conn *Conn, err error) {
+	if !strings.HasSuffix(network, "-tls") {
+		network += "-tls"
+	}
+	client := Client{Net: network, Dialer: &net.Dialer{Timeout: timeout}, TLSConfig: tlsConfig}
+	return client.Dial(address)
+}
+
+// ExchangeContext acts like Exchange, but honors the deadline on the provided
+// context, if present. If there is both a context deadline and a configured
+// timeout on the client, the earliest of the two takes effect.
+func (c *Client) ExchangeContext(ctx context.Context, m *Msg, a string) (r *Msg, rtt time.Duration, err error) {
+	conn, err := c.DialContext(ctx, a)
 	if err != nil {
-		return nil, err
+		return nil, 0, err
 	}
-	return conn, nil
+	defer conn.Close()
+
+	return c.exchangeWithConnContext(ctx, m, conn)
 }

vendor/github.com/miekg/dns/clientconfig.go

@@ -2,6 +2,7 @@ package dns
 
 import (
 	"bufio"
+	"io"
 	"os"
 	"strconv"
 	"strings"
@@ -25,8 +26,13 @@ func ClientConfigFromFile(resolvconf string) (*ClientConfig, error) {
 		return nil, err
 	}
 	defer file.Close()
+	return ClientConfigFromReader(file)
+}
+
+// ClientConfigFromReader works like ClientConfigFromFile but takes an io.Reader as argument
+func ClientConfigFromReader(resolvconf io.Reader) (*ClientConfig, error) {
 	c := new(ClientConfig)
-	scanner := bufio.NewScanner(file)
+	scanner := bufio.NewScanner(resolvconf)
 	c.Servers = make([]string, 0)
 	c.Search = make([]string, 0)
 	c.Port = "53"
@@ -62,19 +68,17 @@ func ClientConfigFromFile(resolvconf string) (*ClientConfig, error) {
 			}
 
 		case "search": // set search path to given servers
-			c.Search = make([]string, len(f)-1)
-			for i := 0; i < len(c.Search); i++ {
-				c.Search[i] = f[i+1]
-			}
+			c.Search = append([]string(nil), f[1:]...)
 
 		case "options": // magic options
-			for i := 1; i < len(f); i++ {
-				s := f[i]
+			for _, s := range f[1:] {
 				switch {
 				case len(s) >= 6 && s[:6] == "ndots:":
 					n, _ := strconv.Atoi(s[6:])
-					if n < 1 {
-						n = 1
+					if n < 0 {
+						n = 0
+					} else if n > 15 {
+						n = 15
 					}
 					c.Ndots = n
 				case len(s) >= 8 && s[:8] == "timeout:":
@@ -83,7 +87,7 @@ func ClientConfigFromFile(resolvconf string) (*ClientConfig, error) {
 						n = 1
 					}
 					c.Timeout = n
-				case len(s) >= 8 && s[:9] == "attempts:":
+				case len(s) >= 9 && s[:9] == "attempts:":
 					n, _ := strconv.Atoi(s[9:])
 					if n < 1 {
 						n = 1
@@ -97,3 +101,35 @@ func ClientConfigFromFile(resolvconf string) (*ClientConfig, error) {
 	}
 	return c, nil
 }
+
+// NameList returns all of the names that should be queried based on the
+// config. It is based off of go's net/dns name building, but it does not
+// check the length of the resulting names.
+func (c *ClientConfig) NameList(name string) []string {
+	// if this domain is already fully qualified, no append needed.
+	if IsFqdn(name) {
+		return []string{name}
+	}
+
+	// Check to see if the name has more labels than Ndots. Do this before making
+	// the domain fully qualified.
+	hasNdots := CountLabel(name) > c.Ndots
+	// Make the domain fully qualified.
+	name = Fqdn(name)
+
+	// Make a list of names based off search.
+	names := []string{}
+
+	// If name has enough dots, try that first.
+	if hasNdots {
+		names = append(names, name)
+	}
+	for _, s := range c.Search {
+		names = append(names, Fqdn(name+s))
+	}
+	// If we didn't have enough dots, try after suffixes.
+	if !hasNdots {
+		names = append(names, name)
+	}
+	return names
+}

vendor/github.com/miekg/dns/dane.go

+package dns
+
+import (
+	"crypto/sha256"
+	"crypto/sha512"
+	"crypto/x509"
+	"encoding/hex"
+	"errors"
+)
+
+// CertificateToDANE converts a certificate to a hex string as used in the TLSA or SMIMEA records.
+func CertificateToDANE(selector, matchingType uint8, cert *x509.Certificate) (string, error) {
+	switch matchingType {
+	case 0:
+		switch selector {
+		case 0:
+			return hex.EncodeToString(cert.Raw), nil
+		case 1:
+			return hex.EncodeToString(cert.RawSubjectPublicKeyInfo), nil
+		}
+	case 1:
+		h := sha256.New()
+		switch selector {
+		case 0:
+			h.Write(cert.Raw)
+			return hex.EncodeToString(h.Sum(nil)), nil
+		case 1:
+			h.Write(cert.RawSubjectPublicKeyInfo)
+			return hex.EncodeToString(h.Sum(nil)), nil
+		}
+	case 2:
+		h := sha512.New()
+		switch selector {
+		case 0:
+			h.Write(cert.Raw)
+			return hex.EncodeToString(h.Sum(nil)), nil
+		case 1:
+			h.Write(cert.RawSubjectPublicKeyInfo)
+			return hex.EncodeToString(h.Sum(nil)), nil
+		}
+	}
+	return "", errors.New("dns: bad MatchingType or Selector")
+}

vendor/github.com/miekg/dns/defaults.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"net"
 	"strconv"
+	"strings"
 )
 
 const hexDigit = "0123456789abcdef"
@@ -13,9 +14,12 @@ const hexDigit = "0123456789abcdef"
 // SetReply creates a reply message from a request message.
 func (dns *Msg) SetReply(request *Msg) *Msg {
 	dns.Id = request.Id
-	dns.RecursionDesired = request.RecursionDesired // Copy rd bit
 	dns.Response = true
-	dns.Opcode = OpcodeQuery
+	dns.Opcode = request.Opcode
+	if dns.Opcode == OpcodeQuery {
+		dns.RecursionDesired = request.RecursionDesired // Copy rd bit
+		dns.CheckingDisabled = request.CheckingDisabled // Copy cd bit
+	}
 	dns.Rcode = RcodeSuccess
 	if len(request.Question) > 0 {
 		dns.Question = make([]Question, 1)
@@ -101,12 +105,12 @@ func (dns *Msg) SetAxfr(z string) *Msg {
 
 // SetTsig appends a TSIG RR to the message.
 // This is only a skeleton TSIG RR that is added as the last RR in the
-// additional section. The Tsig is calculated when the message is being send.
-func (dns *Msg) SetTsig(z, algo string, fudge, timesigned int64) *Msg {
+// additional section. The TSIG is calculated when the message is being send.
+func (dns *Msg) SetTsig(z, algo string, fudge uint16, timesigned int64) *Msg {
 	t := new(TSIG)
 	t.Hdr = RR_Header{z, TypeTSIG, ClassANY, 0, 0}
 	t.Algorithm = algo
-	t.Fudge = 300
+	t.Fudge = fudge
 	t.TimeSigned = uint64(timesigned)
 	t.OrigId = dns.Id
 	dns.Extra = append(dns.Extra, t)
@@ -142,9 +146,27 @@ func (dns *Msg) IsTsig() *TSIG {
 // record in the additional section will do. It returns the OPT record
 // found or nil.
 func (dns *Msg) IsEdns0() *OPT {
-	for _, r := range dns.Extra {
-		if r.Header().Rrtype == TypeOPT {
-			return r.(*OPT)
+	// RFC 6891, Section 6.1.1 allows the OPT record to appear
+	// anywhere in the additional record section, but it's usually at
+	// the end so start there.
+	for i := len(dns.Extra) - 1; i >= 0; i-- {
+		if dns.Extra[i].Header().Rrtype == TypeOPT {
+			return dns.Extra[i].(*OPT)
+		}
+	}
+	return nil
+}
+
+// popEdns0 is like IsEdns0, but it removes the record from the message.
+func (dns *Msg) popEdns0() *OPT {
+	// RFC 6891, Section 6.1.1 allows the OPT record to appear
+	// anywhere in the additional record section, but it's usually at
+	// the end so start there.
+	for i := len(dns.Extra) - 1; i >= 0; i-- {
+		if dns.Extra[i].Header().Rrtype == TypeOPT {
+			opt := dns.Extra[i].(*OPT)
+			dns.Extra = append(dns.Extra[:i], dns.Extra[i+1:]...)
+			return opt
 		}
 	}
 	return nil
@@ -156,15 +178,81 @@ func (dns *Msg) IsEdns0() *OPT {
 // the number of labels.  When false is returned the number of labels is not
 // defined.  Also note that this function is extremely liberal; almost any
 // string is a valid domain name as the DNS is 8 bit protocol. It checks if each
-// label fits in 63 characters, but there is no length check for the entire
-// string s. I.e.  a domain name longer than 255 characters is considered valid.
+// label fits in 63 characters and that the entire name will fit into the 255
+// octet wire format limit.
 func IsDomainName(s string) (labels int, ok bool) {
-	_, labels, err := packDomainName(s, nil, 0, nil, false)
-	return labels, err == nil
+	// XXX: The logic in this function was copied from packDomainName and
+	// should be kept in sync with that function.
+
+	const lenmsg = 256
+
+	if len(s) == 0 { // Ok, for instance when dealing with update RR without any rdata.
+		return 0, false
+	}
+
+	s = Fqdn(s)
+
+	// Each dot ends a segment of the name. Except for escaped dots (\.), which
+	// are normal dots.
+
+	var (
+		off    int
+		begin  int
+		wasDot bool
+	)
+	for i := 0; i < len(s); i++ {
+		switch s[i] {
+		case '\\':
+			if off+1 > lenmsg {
+				return labels, false
+			}
+
+			// check for \DDD
+			if i+3 < len(s) && isDigit(s[i+1]) && isDigit(s[i+2]) && isDigit(s[i+3]) {
+				i += 3
+				begin += 3
+			} else {
+				i++
+				begin++
+			}
+
+			wasDot = false
+		case '.':
+			if i == 0 && len(s) > 1 {
+				// leading dots are not legal except for the root zone
+				return labels, false
+			}
+
+			if wasDot {
+				// two dots back to back is not legal
+				return labels, false
+			}
+			wasDot = true
+
+			labelLen := i - begin
+			if labelLen >= 1<<6 { // top two bits of length must be clear
+				return labels, false
+			}
+
+			// off can already (we're in a loop) be bigger than lenmsg
+			// this happens when a name isn't fully qualified
+			off += 1 + labelLen
+			if off > lenmsg {
+				return labels, false
+			}
+
+			labels++
+			begin = i + 1
+		default:
+			wasDot = false
+		}
+	}
+
+	return labels, true
 }
 
-// IsSubDomain checks if child is indeed a child of the parent. Both child and
-// parent are *not* downcased before doing the comparison.
+// IsSubDomain checks if child is indeed a child of the parent. If child and parent
+// are the same domain true is returned as well.
 func IsSubDomain(parent, child string) bool {
 	// Entire child is contained in parent
 	return CompareDomainName(parent, child) == CountLabel(parent)
@@ -174,7 +262,7 @@ func IsSubDomain(parent, child string) bool {
 // The checking is performed on the binary payload.
 func IsMsg(buf []byte) error {
 	// Header
-	if len(buf) < 12 {
+	if len(buf) < headerSize {
 		return errors.New("dns: bad message header")
 	}
 	// Header: Opcode
@@ -184,11 +272,18 @@ func IsMsg(buf []byte) error {
 
 // IsFqdn checks if a domain name is fully qualified.
 func IsFqdn(s string) bool {
-	l := len(s)
-	if l == 0 {
+	s2 := strings.TrimSuffix(s, ".")
+	if s == s2 {
 		return false
 	}
-	return s[l-1] == '.'
+
+	i := strings.LastIndexFunc(s2, func(r rune) bool {
+		return r != '\\'
+	})
+
+	// Test whether we have an even number of escape sequences before
+	// the dot or none.
+	return (len(s2)-i)%2 != 0
 }
 
 // IsRRset checks if a set of RRs is a valid RRset as defined by RFC 2181.
@@ -227,6 +322,12 @@ func Fqdn(s string) string {
 	return s + "."
 }
 
+// CanonicalName returns the domain name in canonical form. A name in canonical
+// form is lowercase and fully qualified. See Section 6.2 in RFC 4034.
+func CanonicalName(s string) string {
+	return strings.ToLower(Fqdn(s))
+}
+
 // Copied from the official Go code.
 
 // ReverseAddr returns the in-addr.arpa. or ip6.arpa. hostname of the IP
@@ -237,19 +338,23 @@ func ReverseAddr(addr string) (arpa string, err error) {
 	if ip == nil {
 		return "", &Error{err: "unrecognized address: " + addr}
 	}
-	if ip.To4() != nil {
-		return strconv.Itoa(int(ip[15])) + "." + strconv.Itoa(int(ip[14])) + "." + strconv.Itoa(int(ip[13])) + "." +
-			strconv.Itoa(int(ip[12])) + ".in-addr.arpa.", nil
+	if v4 := ip.To4(); v4 != nil {
+		buf := make([]byte, 0, net.IPv4len*4+len("in-addr.arpa."))
+		// Add it, in reverse, to the buffer
+		for i := len(v4) - 1; i >= 0; i-- {
+			buf = strconv.AppendInt(buf, int64(v4[i]), 10)
+			buf = append(buf, '.')
+		}
+		// Append "in-addr.arpa." and return (buf already has the final .)
+		buf = append(buf, "in-addr.arpa."...)
+		return string(buf), nil
 	}
 	// Must be IPv6
-	buf := make([]byte, 0, len(ip)*4+len("ip6.arpa."))
+	buf := make([]byte, 0, net.IPv6len*4+len("ip6.arpa."))
 	// Add it, in reverse, to the buffer
 	for i := len(ip) - 1; i >= 0; i-- {
 		v := ip[i]
-		buf = append(buf, hexDigit[v&0xF])
-		buf = append(buf, '.')
-		buf = append(buf, hexDigit[v>>4])
-		buf = append(buf, '.')
+		buf = append(buf, hexDigit[v&0xF], '.', hexDigit[v>>4], '.')
 	}
 	// Append "ip6.arpa." and return (buf already has the final .)
 	buf = append(buf, "ip6.arpa."...)
@@ -266,8 +371,11 @@ func (t Type) String() string {
 
 // String returns the string representation for the class c.
 func (c Class) String() string {
-	if c1, ok := ClassToString[uint16(c)]; ok {
-		return c1
+	if s, ok := ClassToString[uint16(c)]; ok {
+		// Only emit mnemonics when they are unambiguous, specially ANY is in both.
+		if _, ok := StringToType[s]; !ok {
+			return s
+		}
 	}
 	return "CLASS" + strconv.Itoa(int(c))
 }

vendor/github.com/miekg/dns/dns.go

 package dns
 
-import "strconv"
+import (
+	"encoding/hex"
+	"strconv"
+)
 
 const (
-	year68 = 1 << 31 // For RFC1982 (Serial Arithmetic) calculations in 32 bits.
+	year68     = 1 << 31 // For RFC1982 (Serial Arithmetic) calculations in 32 bits.
+	defaultTtl = 3600    // Default internal TTL.
+
 	// DefaultMsgSize is the standard default for messages larger than 512 bytes.
 	DefaultMsgSize = 4096
 	// MinMsgSize is the minimal size of a DNS packet.
 	MinMsgSize = 512
 	// MaxMsgSize is the largest possible DNS packet.
 	MaxMsgSize = 65535
-	defaultTtl = 3600 // Default internal TTL.
 )
 
-// Error represents a DNS error
+// Error represents a DNS error.
 type Error struct{ err string }
 
 func (e *Error) Error() string {
@@ -30,10 +34,33 @@ type RR interface {
 	Header() *RR_Header
 	// String returns the text representation of the resource record.
 	String() string
+
 	// copy returns a copy of the RR
 	copy() RR
-	// len returns the length (in octets) of the uncompressed RR in wire format.
-	len() int
+
+	// len returns the length (in octets) of the compressed or uncompressed RR in wire format.
+	//
+	// If compression is nil, the uncompressed size will be returned, otherwise the compressed
+	// size will be returned and domain names will be added to the map for future compression.
+	len(off int, compression map[string]struct{}) int
+
+	// pack packs the records RDATA into wire format. The header will
+	// already have been packed into msg.
+	pack(msg []byte, off int, compression compressionMap, compress bool) (off1 int, err error)
+
+	// unpack unpacks an RR from wire format.
+	//
+	// This will only be called on a new and empty RR type with only the header populated. It
+	// will only be called if the record's RDATA is non-empty.
+	unpack(msg []byte, off int) (off1 int, err error)
+
+	// parse parses an RR from zone file format.
+	//
+	// This will only be called on a new and empty RR type with only the header populated.
+	parse(c *zlexer, origin string) *ParseError
+
+	// isDuplicate returns whether the two RRs are duplicates.
+	isDuplicate(r2 RR) bool
 }
 
 // RR_Header is the header all DNS resource records share.
@@ -42,25 +69,15 @@ type RR_Header struct {
 	Rrtype   uint16
 	Class    uint16
 	Ttl      uint32
-	Rdlength uint16 // length of data after header
+	Rdlength uint16 // Length of data after header.
 }
 
-// Header returns itself. This is here to make RR_Header implement the RR interface.
+// Header returns itself. This is here to make RR_Header implements the RR interface.
 func (h *RR_Header) Header() *RR_Header { return h }
 
-// Just to imlement the RR interface.
+// Just to implement the RR interface.
 func (h *RR_Header) copy() RR { return nil }
 
-func (h *RR_Header) copyHeader() *RR_Header {
-	r := new(RR_Header)
-	r.Name = h.Name
-	r.Rrtype = h.Rrtype
-	r.Class = h.Class
-	r.Ttl = h.Ttl
-	r.Rdlength = h.Rdlength
-	return r
-}
-
 func (h *RR_Header) String() string {
 	var s string
 
@@ -76,25 +93,66 @@ func (h *RR_Header) String() string {
 	return s
 }
 
-func (h *RR_Header) len() int {
-	l := len(h.Name) + 1
+func (h *RR_Header) len(off int, compression map[string]struct{}) int {
+	l := domainNameLen(h.Name, off, compression, true)
 	l += 10 // rrtype(2) + class(2) + ttl(4) + rdlength(2)
 	return l
 }
 
-// ToRFC3597 converts a known RR to the unknown RR representation
-// from RFC 3597.
+func (h *RR_Header) pack(msg []byte, off int, compression compressionMap, compress bool) (off1 int, err error) {
+	// RR_Header has no RDATA to pack.
+	return off, nil
+}
+
+func (h *RR_Header) unpack(msg []byte, off int) (int, error) {
+	panic("dns: internal error: unpack should never be called on RR_Header")
+}
+
+func (h *RR_Header) parse(c *zlexer, origin string) *ParseError {
+	panic("dns: internal error: parse should never be called on RR_Header")
+}
+
+// ToRFC3597 converts a known RR to the unknown RR representation from RFC 3597.
 func (rr *RFC3597) ToRFC3597(r RR) error {
-	buf := make([]byte, r.len()*2)
-	off, err := PackStruct(r, buf, 0)
+	buf := make([]byte, Len(r))
+	headerEnd, off, err := packRR(r, buf, 0, compressionMap{}, false)
 	if err != nil {
 		return err
 	}
 	buf = buf[:off]
-	rawSetRdlength(buf, 0, off)
-	_, err = UnpackStruct(rr, buf, 0)
+
+	*rr = RFC3597{Hdr: *r.Header()}
+	rr.Hdr.Rdlength = uint16(off - headerEnd)
+
+	if noRdata(rr.Hdr) {
+		return nil
+	}
+
+	_, err = rr.unpack(buf, headerEnd)
+	return err
+}
+
+// fromRFC3597 converts an unknown RR representation from RFC 3597 to the known RR type.
+func (rr *RFC3597) fromRFC3597(r RR) error {
+	hdr := r.Header()
+	*hdr = rr.Hdr
+
+	// Can't overflow uint16 as the length of Rdata is validated in (*RFC3597).parse.
+	// We can only get here when rr was constructed with that method.
+	hdr.Rdlength = uint16(hex.DecodedLen(len(rr.Rdata)))
+
+	if noRdata(*hdr) {
+		// Dynamic update.
+		return nil
+	}
+
+	// rr.pack requires an extra allocation and a copy so we just decode Rdata
+	// manually, it's simpler anyway.
+	msg, err := hex.DecodeString(rr.Rdata)
 	if err != nil {
 		return err
 	}
-	return nil
+
+	_, err = r.unpack(msg, 0)
+	return err
 }

vendor/github.com/miekg/dns/dnssec.go

@@ -3,16 +3,16 @@ package dns
 import (
 	"bytes"
 	"crypto"
-	"crypto/dsa"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/elliptic"
-	_ "crypto/md5"
 	"crypto/rand"
 	"crypto/rsa"
-	_ "crypto/sha1"
-	_ "crypto/sha256"
-	_ "crypto/sha512"
+	_ "crypto/sha1"   // need its init function
+	_ "crypto/sha256" // need its init function
+	_ "crypto/sha512" // need its init function
 	"encoding/asn1"
+	"encoding/binary"
 	"encoding/hex"
 	"math/big"
 	"sort"
@@ -37,12 +37,14 @@ const (
 	ECCGOST
 	ECDSAP256SHA256
 	ECDSAP384SHA384
+	ED25519
+	ED448
 	INDIRECT   uint8 = 252
 	PRIVATEDNS uint8 = 253 // Private (experimental keys)
 	PRIVATEOID uint8 = 254
 )
 
-// Map for algorithm names.
+// AlgorithmToString is a map of algorithm IDs to algorithm names.
 var AlgorithmToString = map[uint8]string{
 	RSAMD5:           "RSAMD5",
 	DH:               "DH",
@@ -55,23 +57,27 @@ var AlgorithmToString = map[uint8]string{
 	ECCGOST:          "ECC-GOST",
 	ECDSAP256SHA256:  "ECDSAP256SHA256",
 	ECDSAP384SHA384:  "ECDSAP384SHA384",
+	ED25519:          "ED25519",
+	ED448:            "ED448",
 	INDIRECT:         "INDIRECT",
 	PRIVATEDNS:       "PRIVATEDNS",
 	PRIVATEOID:       "PRIVATEOID",
 }
 
-// Map of algorithm strings.
-var StringToAlgorithm = reverseInt8(AlgorithmToString)
-
-// Map of algorithm crypto hashes.
+// AlgorithmToHash is a map of algorithm crypto hash IDs to crypto.Hash's.
+// For newer algorithm that do their own hashing (i.e. ED25519) the returned value
+// is 0, implying no (external) hashing should occur. The non-exported identityHash is then
+// used.
 var AlgorithmToHash = map[uint8]crypto.Hash{
 	RSAMD5:           crypto.MD5, // Deprecated in RFC 6725
+	DSA:              crypto.SHA1,
 	RSASHA1:          crypto.SHA1,
 	RSASHA1NSEC3SHA1: crypto.SHA1,
 	RSASHA256:        crypto.SHA256,
 	ECDSAP256SHA256:  crypto.SHA256,
 	ECDSAP384SHA384:  crypto.SHA384,
 	RSASHA512:        crypto.SHA512,
+	ED25519:          0,
 }
 
 // DNSSEC hashing algorithm codes.
@@ -84,7 +90,7 @@ const (
 	SHA512       // Experimental
 )
 
-// Map for hash names.
+// HashToString is a map of hash IDs to names.
 var HashToString = map[uint8]string{
 	SHA1:   "SHA1",
 	SHA256: "SHA256",
@@ -93,9 +99,6 @@ var HashToString = map[uint8]string{
 	SHA512: "SHA512",
 }
 
-// Map of hash strings.
-var StringToHash = reverseInt8(HashToString)
-
 // DNSKEY flag values.
 const (
 	SEP    = 1
@@ -103,9 +106,7 @@ const (
 	ZONE   = 1 << 8
 )
 
-// The RRSIG needs to be converted to wireformat with some of
-// the rdata (the signature) missing. Use this struct to easy
-// the conversion (and re-use the pack/unpack functions).
+// The RRSIG needs to be converted to wireformat with some of the rdata (the signature) missing.
 type rrsigWireFmt struct {
 	TypeCovered uint16
 	Algorithm   uint8
@@ -139,12 +140,12 @@ func (k *DNSKEY) KeyTag() uint16 {
 	var keytag int
 	switch k.Algorithm {
 	case RSAMD5:
-		// Look at the bottom two bytes of the modules, which the last
-		// item in the pubkey. We could do this faster by looking directly
-		// at the base64 values. But I'm lazy.
+		// This algorithm has been deprecated, but keep this key-tag calculation.
+		// Look at the bottom two bytes of the modules, which the last item in the pubkey.
+		// See https://www.rfc-editor.org/errata/eid193 .
 		modulus, _ := fromBase64([]byte(k.PublicKey))
 		if len(modulus) > 1 {
-			x, _ := unpackUint16(modulus, len(modulus)-2)
+			x := binary.BigEndian.Uint16(modulus[len(modulus)-3:])
 			keytag = int(x)
 		}
 	default:
@@ -154,7 +155,7 @@ func (k *DNSKEY) KeyTag() uint16 {
 		keywire.Algorithm = k.Algorithm
 		keywire.PublicKey = k.PublicKey
 		wire := make([]byte, DefaultMsgSize)
-		n, err := PackStruct(keywire, wire, 0)
+		n, err := packKeyWire(keywire, wire)
 		if err != nil {
 			return 0
 		}
@@ -166,7 +167,7 @@ func (k *DNSKEY) KeyTag() uint16 {
 				keytag += int(v) << 8
 			}
 		}
-		keytag += (keytag >> 16) & 0xFFFF
+		keytag += keytag >> 16 & 0xFFFF
 		keytag &= 0xFFFF
 	}
 	return uint16(keytag)
@@ -192,14 +193,14 @@ func (k *DNSKEY) ToDS(h uint8) *DS {
 	keywire.Algorithm = k.Algorithm
 	keywire.PublicKey = k.PublicKey
 	wire := make([]byte, DefaultMsgSize)
-	n, err := PackStruct(keywire, wire, 0)
+	n, err := packKeyWire(keywire, wire)
 	if err != nil {
 		return nil
 	}
 	wire = wire[:n]
 
 	owner := make([]byte, 255)
-	off, err1 := PackDomainName(strings.ToLower(k.Hdr.Name), owner, 0, nil, false)
+	off, err1 := PackDomainName(CanonicalName(k.Hdr.Name), owner, 0, nil, false)
 	if err1 != nil {
 		return nil
 	}
@@ -209,9 +210,6 @@ func (k *DNSKEY) ToDS(h uint8) *DS {
 	// "|" denotes concatenation
 	// DNSKEY RDATA = Flags | Protocol | Algorithm | Public Key.
 
-	// digest buffer
-	digest := append(owner, wire...) // another copy
-
 	var hash crypto.Hash
 	switch h {
 	case SHA1:
@@ -227,7 +225,8 @@ func (k *DNSKEY) ToDS(h uint8) *DS {
 	}
 
 	s := hash.New()
-	s.Write(digest)
+	s.Write(owner)
+	s.Write(wire)
 	ds.Digest = hex.EncodeToString(s.Sum(nil))
 	return ds
 }
@@ -235,7 +234,7 @@ func (k *DNSKEY) ToDS(h uint8) *DS {
 // ToCDNSKEY converts a DNSKEY record to a CDNSKEY record.
 func (k *DNSKEY) ToCDNSKEY() *CDNSKEY {
 	c := &CDNSKEY{DNSKEY: *k}
-	c.Hdr = *k.Hdr.copyHeader()
+	c.Hdr = k.Hdr
 	c.Hdr.Rrtype = TypeCDNSKEY
 	return c
 }
@@ -243,18 +242,17 @@ func (k *DNSKEY) ToCDNSKEY() *CDNSKEY {
 // ToCDS converts a DS record to a CDS record.
 func (d *DS) ToCDS() *CDS {
 	c := &CDS{DS: *d}
-	c.Hdr = *d.Hdr.copyHeader()
+	c.Hdr = d.Hdr
 	c.Hdr.Rrtype = TypeCDS
 	return c
 }
 
-// Sign signs an RRSet. The signature needs to be filled in with
-// the values: Inception, Expiration, KeyTag, SignerName and Algorithm.
-// The rest is copied from the RRset. Sign returns true when the signing went OK,
-// otherwise false.
-// There is no check if RRSet is a proper (RFC 2181) RRSet.
-// If OrigTTL is non zero, it is used as-is, otherwise the TTL of the RRset
-// is used as the OrigTTL.
+// Sign signs an RRSet. The signature needs to be filled in with the values:
+// Inception, Expiration, KeyTag, SignerName and Algorithm.  The rest is copied
+// from the RRset. Sign returns a non-nill error when the signing went OK.
+// There is no check if RRSet is a proper (RFC 2181) RRSet.  If OrigTTL is non
+// zero, it is used as-is, otherwise the TTL of the RRset is used as the
+// OrigTTL.
 func (rr *RRSIG) Sign(k crypto.Signer, rrset []RR) error {
 	if k == nil {
 		return ErrPrivKey
@@ -264,16 +262,17 @@ func (rr *RRSIG) Sign(k crypto.Signer, rrset []RR) error {
 		return ErrKey
 	}
 
+	h0 := rrset[0].Header()
 	rr.Hdr.Rrtype = TypeRRSIG
-	rr.Hdr.Name = rrset[0].Header().Name
-	rr.Hdr.Class = rrset[0].Header().Class
+	rr.Hdr.Name = h0.Name
+	rr.Hdr.Class = h0.Class
 	if rr.OrigTtl == 0 { // If set don't override
-		rr.OrigTtl = rrset[0].Header().Ttl
+		rr.OrigTtl = h0.Ttl
 	}
-	rr.TypeCovered = rrset[0].Header().Rrtype
-	rr.Labels = uint8(CountLabel(rrset[0].Header().Name))
+	rr.TypeCovered = h0.Rrtype
+	rr.Labels = uint8(CountLabel(h0.Name))
 
-	if strings.HasPrefix(rrset[0].Header().Name, "*") {
+	if strings.HasPrefix(h0.Name, "*") {
 		rr.Labels-- // wildcard, remove from label count
 	}
 
@@ -286,11 +285,11 @@ func (rr *RRSIG) Sign(k crypto.Signer, rrset []RR) error {
 	sigwire.Inception = rr.Inception
 	sigwire.KeyTag = rr.KeyTag
 	// For signing, lowercase this name
-	sigwire.SignerName = strings.ToLower(rr.SignerName)
+	sigwire.SignerName = CanonicalName(rr.SignerName)
 
 	// Create the desired binary blob
 	signdata := make([]byte, DefaultMsgSize)
-	n, err := PackStruct(sigwire, signdata, 0)
+	n, err := packSigWire(sigwire, signdata)
 	if err != nil {
 		return err
 	}
@@ -299,24 +298,28 @@ func (rr *RRSIG) Sign(k crypto.Signer, rrset []RR) error {
 	if err != nil {
 		return err
 	}
-	signdata = append(signdata, wire...)
-
-	hash, ok := AlgorithmToHash[rr.Algorithm]
-	if !ok {
-		return ErrAlg
-	}
-
-	h := hash.New()
-	h.Write(signdata)
 
-	signature, err := sign(k, h.Sum(nil), hash, rr.Algorithm)
+	h, cryptohash, err := hashFromAlgorithm(rr.Algorithm)
 	if err != nil {
 		return err
 	}
 
-	rr.Signature = toBase64(signature)
+	switch rr.Algorithm {
+	case RSAMD5, DSA, DSANSEC3SHA1:
+		// See RFC 6944.
+		return ErrAlg
+	default:
+		h.Write(signdata)
+		h.Write(wire)
+
+		signature, err := sign(k, h.Sum(nil), cryptohash, rr.Algorithm)
+		if err != nil {
+			return err
+		}
 
-	return nil
+		rr.Signature = toBase64(signature)
+		return nil
+	}
 }
 
 func sign(k crypto.Signer, hashed []byte, hash crypto.Hash, alg uint8) ([]byte, error) {
@@ -326,9 +329,8 @@ func sign(k crypto.Signer, hashed []byte, hash crypto.Hash, alg uint8) ([]byte,
 	}
 
 	switch alg {
-	case RSASHA1, RSASHA1NSEC3SHA1, RSASHA256, RSASHA512:
+	case RSASHA1, RSASHA1NSEC3SHA1, RSASHA256, RSASHA512, ED25519:
 		return signature, nil
-
 	case ECDSAP256SHA256, ECDSAP384SHA384:
 		ecdsaSignature := &struct {
 			R, S *big.Int
@@ -348,22 +350,16 @@ func sign(k crypto.Signer, hashed []byte, hash crypto.Hash, alg uint8) ([]byte,
 		signature := intToBytes(ecdsaSignature.R, intlen)
 		signature = append(signature, intToBytes(ecdsaSignature.S, intlen)...)
 		return signature, nil
-
-	// There is no defined interface for what a DSA backed crypto.Signer returns
-	case DSA, DSANSEC3SHA1:
-		// 	t := divRoundUp(divRoundUp(p.PublicKey.Y.BitLen(), 8)-64, 8)
-		// 	signature := []byte{byte(t)}
-		// 	signature = append(signature, intToBytes(r1, 20)...)
-		// 	signature = append(signature, intToBytes(s1, 20)...)
-		// 	rr.Signature = signature
+	default:
+		return nil, ErrAlg
 	}
-
-	return nil, ErrAlg
 }
 
 // Verify validates an RRSet with the signature and key. This is only the
 // cryptographic test, the signature validity period must be checked separately.
 // This function copies the rdata of some RRs (to lowercase domain names) for the validation to work.
+// It also checks that the Zone Key bit (RFC 4034 2.1.1) is set on the DNSKEY
+// and that the Protocol field is set to 3 (RFC 4034 2.1.2).
 func (rr *RRSIG) Verify(k *DNSKEY, rrset []RR) error {
 	// First the easy checks
 	if !IsRRset(rrset) {
@@ -378,20 +374,23 @@ func (rr *RRSIG) Verify(k *DNSKEY, rrset []RR) error {
 	if rr.Algorithm != k.Algorithm {
 		return ErrKey
 	}
-	if strings.ToLower(rr.SignerName) != strings.ToLower(k.Hdr.Name) {
+	if !strings.EqualFold(rr.SignerName, k.Hdr.Name) {
 		return ErrKey
 	}
 	if k.Protocol != 3 {
 		return ErrKey
 	}
+	// RFC 4034 2.1.1 If bit 7 has value 0, then the DNSKEY record holds some
+	// other type of DNS public key and MUST NOT be used to verify RRSIGs that
+	// cover RRsets.
+	if k.Flags&ZONE == 0 {
+		return ErrKey
+	}
 
 	// IsRRset checked that we have at least one RR and that the RRs in
 	// the set have consistent type, class, and name. Also check that type and
 	// class matches the RRSIG record.
-	if rrset[0].Header().Class != rr.Hdr.Class {
-		return ErrRRset
-	}
-	if rrset[0].Header().Rrtype != rr.TypeCovered {
+	if h0 := rrset[0].Header(); h0.Class != rr.Hdr.Class || h0.Rrtype != rr.TypeCovered {
 		return ErrRRset
 	}
 
@@ -405,10 +404,10 @@ func (rr *RRSIG) Verify(k *DNSKEY, rrset []RR) error {
 	sigwire.Expiration = rr.Expiration
 	sigwire.Inception = rr.Inception
 	sigwire.KeyTag = rr.KeyTag
-	sigwire.SignerName = strings.ToLower(rr.SignerName)
+	sigwire.SignerName = CanonicalName(rr.SignerName)
 	// Create the desired binary blob
 	signeddata := make([]byte, DefaultMsgSize)
-	n, err := PackStruct(sigwire, signeddata, 0)
+	n, err := packSigWire(sigwire, signeddata)
 	if err != nil {
 		return err
 	}
@@ -417,30 +416,29 @@ func (rr *RRSIG) Verify(k *DNSKEY, rrset []RR) error {
 	if err != nil {
 		return err
 	}
-	signeddata = append(signeddata, wire...)
 
 	sigbuf := rr.sigBuf()           // Get the binary signature data
 	if rr.Algorithm == PRIVATEDNS { // PRIVATEOID
-		// TODO(mg)
-		// remove the domain name and assume its our
+		// TODO(miek)
+		// remove the domain name and assume its ours?
 	}
 
-	hash, ok := AlgorithmToHash[rr.Algorithm]
-	if !ok {
-		return ErrAlg
+	h, cryptohash, err := hashFromAlgorithm(rr.Algorithm)
+	if err != nil {
+		return err
 	}
 
 	switch rr.Algorithm {
-	case RSASHA1, RSASHA1NSEC3SHA1, RSASHA256, RSASHA512, RSAMD5:
+	case RSASHA1, RSASHA1NSEC3SHA1, RSASHA256, RSASHA512:
 		// TODO(mg): this can be done quicker, ie. cache the pubkey data somewhere??
 		pubkey := k.publicKeyRSA() // Get the key
 		if pubkey == nil {
 			return ErrKey
 		}
 
-		h := hash.New()
 		h.Write(signeddata)
-		return rsa.VerifyPKCS1v15(pubkey, hash, h.Sum(nil), sigbuf)
+		h.Write(wire)
+		return rsa.VerifyPKCS1v15(pubkey, cryptohash, h.Sum(nil), sigbuf)
 
 	case ECDSAP256SHA256, ECDSAP384SHA384:
 		pubkey := k.publicKeyECDSA()
@@ -452,13 +450,24 @@ func (rr *RRSIG) Verify(k *DNSKEY, rrset []RR) error {
 		r := new(big.Int).SetBytes(sigbuf[:len(sigbuf)/2])
 		s := new(big.Int).SetBytes(sigbuf[len(sigbuf)/2:])
 
-		h := hash.New()
 		h.Write(signeddata)
+		h.Write(wire)
 		if ecdsa.Verify(pubkey, h.Sum(nil), r, s) {
 			return nil
 		}
 		return ErrSig
 
+	case ED25519:
+		pubkey := k.publicKeyED25519()
+		if pubkey == nil {
+			return ErrKey
+		}
+
+		if ed25519.Verify(pubkey, append(signeddata, wire...), sigbuf) {
+			return nil
+		}
+		return ErrSig
+
 	default:
 		return ErrAlg
 	}
@@ -477,12 +486,12 @@ func (rr *RRSIG) ValidityPeriod(t time.Time) bool {
 	}
 	modi := (int64(rr.Inception) - utc) / year68
 	mode := (int64(rr.Expiration) - utc) / year68
-	ti := int64(rr.Inception) + (modi * year68)
-	te := int64(rr.Expiration) + (mode * year68)
+	ti := int64(rr.Inception) + modi*year68
+	te := int64(rr.Expiration) + mode*year68
 	return ti <= utc && utc <= te
 }
 
-// Return the signatures base64 encodedig sigdata as a byte slice.
+// Return the signatures base64 encoding sigdata as a byte slice.
 func (rr *RRSIG) sigBuf() []byte {
 	sigbuf, err := fromBase64([]byte(rr.Signature))
 	if err != nil {
@@ -498,6 +507,11 @@ func (k *DNSKEY) publicKeyRSA() *rsa.PublicKey {
 		return nil
 	}
 
+	if len(keybuf) < 1+1+64 {
+		// Exponent must be at least 1 byte and modulus at least 64
+		return nil
+	}
+
 	// RFC 2537/3110, section 2. RSA Public KEY Resource Records
 	// Length is in the 0th byte, unless its zero, then it
 	// it in bytes 1 and 2 and its a 16 bit number
@@ -507,25 +521,35 @@ func (k *DNSKEY) publicKeyRSA() *rsa.PublicKey {
 		explen = uint16(keybuf[1])<<8 | uint16(keybuf[2])
 		keyoff = 3
 	}
+
+	if explen > 4 || explen == 0 || keybuf[keyoff] == 0 {
+		// Exponent larger than supported by the crypto package,
+		// empty, or contains prohibited leading zero.
+		return nil
+	}
+
+	modoff := keyoff + int(explen)
+	modlen := len(keybuf) - modoff
+	if modlen < 64 || modlen > 512 || keybuf[modoff] == 0 {
+		// Modulus is too small, large, or contains prohibited leading zero.
+		return nil
+	}
+
 	pubkey := new(rsa.PublicKey)
 
-	pubkey.N = big.NewInt(0)
-	shift := uint64((explen - 1) * 8)
-	expo := uint64(0)
-	for i := int(explen - 1); i > 0; i-- {
-		expo += uint64(keybuf[keyoff+i]) << shift
-		shift -= 8
-	}
-	// Remainder
-	expo += uint64(keybuf[keyoff])
-	if expo > 2<<31 {
-		// Larger expo than supported.
-		// println("dns: F5 primes (or larger) are not supported")
+	var expo uint64
+	// The exponent of length explen is between keyoff and modoff.
+	for _, v := range keybuf[keyoff:modoff] {
+		expo <<= 8
+		expo |= uint64(v)
+	}
+	if expo > 1<<31-1 {
+		// Larger exponent than supported by the crypto package.
 		return nil
 	}
-	pubkey.E = int(expo)
 
-	pubkey.N.SetBytes(keybuf[keyoff+int(explen):])
+	pubkey.E = int(expo)
+	pubkey.N = new(big.Int).SetBytes(keybuf[modoff:])
 	return pubkey
 }
 
@@ -550,35 +574,20 @@ func (k *DNSKEY) publicKeyECDSA() *ecdsa.PublicKey {
 			return nil
 		}
 	}
-	pubkey.X = big.NewInt(0)
-	pubkey.X.SetBytes(keybuf[:len(keybuf)/2])
-	pubkey.Y = big.NewInt(0)
-	pubkey.Y.SetBytes(keybuf[len(keybuf)/2:])
+	pubkey.X = new(big.Int).SetBytes(keybuf[:len(keybuf)/2])
+	pubkey.Y = new(big.Int).SetBytes(keybuf[len(keybuf)/2:])
 	return pubkey
 }
 
-func (k *DNSKEY) publicKeyDSA() *dsa.PublicKey {
+func (k *DNSKEY) publicKeyED25519() ed25519.PublicKey {
 	keybuf, err := fromBase64([]byte(k.PublicKey))
 	if err != nil {
 		return nil
 	}
-	if len(keybuf) < 22 {
-		return nil
-	}
-	t, keybuf := int(keybuf[0]), keybuf[1:]
-	size := 64 + t*8
-	q, keybuf := keybuf[:20], keybuf[20:]
-	if len(keybuf) != 3*size {
+	if len(keybuf) != ed25519.PublicKeySize {
 		return nil
 	}
-	p, keybuf := keybuf[:size], keybuf[size:]
-	g, y := keybuf[:size], keybuf[size:]
-	pubkey := new(dsa.PublicKey)
-	pubkey.Parameters.Q = big.NewInt(0).SetBytes(q)
-	pubkey.Parameters.P = big.NewInt(0).SetBytes(p)
-	pubkey.Parameters.G = big.NewInt(0).SetBytes(g)
-	pubkey.Y = big.NewInt(0).SetBytes(y)
-	return pubkey
+	return keybuf
 }
 
 type wireSlice [][]byte
@@ -596,51 +605,74 @@ func rawSignatureData(rrset []RR, s *RRSIG) (buf []byte, err error) {
 	wires := make(wireSlice, len(rrset))
 	for i, r := range rrset {
 		r1 := r.copy()
-		r1.Header().Ttl = s.OrigTtl
-		labels := SplitDomainName(r1.Header().Name)
+		h := r1.Header()
+		h.Ttl = s.OrigTtl
+		labels := SplitDomainName(h.Name)
 		// 6.2. Canonical RR Form. (4) - wildcards
 		if len(labels) > int(s.Labels) {
 			// Wildcard
-			r1.Header().Name = "*." + strings.Join(labels[len(labels)-int(s.Labels):], ".") + "."
+			h.Name = "*." + strings.Join(labels[len(labels)-int(s.Labels):], ".") + "."
 		}
 		// RFC 4034: 6.2.  Canonical RR Form. (2) - domain name to lowercase
-		r1.Header().Name = strings.ToLower(r1.Header().Name)
+		h.Name = CanonicalName(h.Name)
 		// 6.2. Canonical RR Form. (3) - domain rdata to lowercase.
 		//   NS, MD, MF, CNAME, SOA, MB, MG, MR, PTR,
 		//   HINFO, MINFO, MX, RP, AFSDB, RT, SIG, PX, NXT, NAPTR, KX,
 		//   SRV, DNAME, A6
+		//
+		// RFC 6840 - Clarifications and Implementation Notes for DNS Security (DNSSEC):
+		//	Section 6.2 of [RFC4034] also erroneously lists HINFO as a record
+		//	that needs conversion to lowercase, and twice at that.  Since HINFO
+		//	records contain no domain names, they are not subject to case
+		//	conversion.
 		switch x := r1.(type) {
 		case *NS:
-			x.Ns = strings.ToLower(x.Ns)
+			x.Ns = CanonicalName(x.Ns)
+		case *MD:
+			x.Md = CanonicalName(x.Md)
+		case *MF:
+			x.Mf = CanonicalName(x.Mf)
 		case *CNAME:
-			x.Target = strings.ToLower(x.Target)
+			x.Target = CanonicalName(x.Target)
 		case *SOA:
-			x.Ns = strings.ToLower(x.Ns)
-			x.Mbox = strings.ToLower(x.Mbox)
+			x.Ns = CanonicalName(x.Ns)
+			x.Mbox = CanonicalName(x.Mbox)
 		case *MB:
-			x.Mb = strings.ToLower(x.Mb)
+			x.Mb = CanonicalName(x.Mb)
 		case *MG:
-			x.Mg = strings.ToLower(x.Mg)
+			x.Mg = CanonicalName(x.Mg)
 		case *MR:
-			x.Mr = strings.ToLower(x.Mr)
+			x.Mr = CanonicalName(x.Mr)
 		case *PTR:
-			x.Ptr = strings.ToLower(x.Ptr)
+			x.Ptr = CanonicalName(x.Ptr)
 		case *MINFO:
-			x.Rmail = strings.ToLower(x.Rmail)
-			x.Email = strings.ToLower(x.Email)
+			x.Rmail = CanonicalName(x.Rmail)
+			x.Email = CanonicalName(x.Email)
 		case *MX:
-			x.Mx = strings.ToLower(x.Mx)
+			x.Mx = CanonicalName(x.Mx)
+		case *RP:
+			x.Mbox = CanonicalName(x.Mbox)
+			x.Txt = CanonicalName(x.Txt)
+		case *AFSDB:
+			x.Hostname = CanonicalName(x.Hostname)
+		case *RT:
+			x.Host = CanonicalName(x.Host)
+		case *SIG:
+			x.SignerName = CanonicalName(x.SignerName)
+		case *PX:
+			x.Map822 = CanonicalName(x.Map822)
+			x.Mapx400 = CanonicalName(x.Mapx400)
 		case *NAPTR:
-			x.Replacement = strings.ToLower(x.Replacement)
+			x.Replacement = CanonicalName(x.Replacement)
 		case *KX:
-			x.Exchanger = strings.ToLower(x.Exchanger)
+			x.Exchanger = CanonicalName(x.Exchanger)
 		case *SRV:
-			x.Target = strings.ToLower(x.Target)
+			x.Target = CanonicalName(x.Target)
 		case *DNAME:
-			x.Target = strings.ToLower(x.Target)
+			x.Target = CanonicalName(x.Target)
 		}
 		// 6.2. Canonical RR Form. (5) - origTTL
-		wire := make([]byte, r1.len()+1) // +1 to be safe(r)
+		wire := make([]byte, Len(r1)+1) // +1 to be safe(r)
 		off, err1 := PackRR(r1, wire, 0, nil, false)
 		if err1 != nil {
 			return nil, err1
@@ -657,3 +689,61 @@ func rawSignatureData(rrset []RR, s *RRSIG) (buf []byte, err error) {
 	}
 	return buf, nil
 }
+
+func packSigWire(sw *rrsigWireFmt, msg []byte) (int, error) {
+	// copied from zmsg.go RRSIG packing
+	off, err := packUint16(sw.TypeCovered, msg, 0)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint8(sw.Algorithm, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint8(sw.Labels, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint32(sw.OrigTtl, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint32(sw.Expiration, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint32(sw.Inception, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint16(sw.KeyTag, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = PackDomainName(sw.SignerName, msg, off, nil, false)
+	if err != nil {
+		return off, err
+	}
+	return off, nil
+}
+
+func packKeyWire(dw *dnskeyWireFmt, msg []byte) (int, error) {
+	// copied from zmsg.go DNSKEY packing
+	off, err := packUint16(dw.Flags, msg, 0)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint8(dw.Protocol, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packUint8(dw.Algorithm, msg, off)
+	if err != nil {
+		return off, err
+	}
+	off, err = packStringBase64(dw.PublicKey, msg, off)
+	if err != nil {
+		return off, err
+	}
+	return off, nil
+}

vendor/github.com/miekg/dns/dnssec_keygen.go

@@ -2,8 +2,8 @@ package dns
 
 import (
 	"crypto"
-	"crypto/dsa"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/elliptic"
 	"crypto/rand"
 	"crypto/rsa"
@@ -18,11 +18,7 @@ import (
 // bits should be set to the size of the algorithm.
 func (k *DNSKEY) Generate(bits int) (crypto.PrivateKey, error) {
 	switch k.Algorithm {
-	case DSA, DSANSEC3SHA1:
-		if bits != 1024 {
-			return nil, ErrKeySize
-		}
-	case RSAMD5, RSASHA1, RSASHA256, RSASHA1NSEC3SHA1:
+	case RSASHA1, RSASHA256, RSASHA1NSEC3SHA1:
 		if bits < 512 || bits > 4096 {
 			return nil, ErrKeySize
 		}
@@ -38,23 +34,16 @@ func (k *DNSKEY) Generate(bits int) (crypto.PrivateKey, error) {
 		if bits != 384 {
 			return nil, ErrKeySize
 		}
+	case ED25519:
+		if bits != 256 {
+			return nil, ErrKeySize
+		}
+	default:
+		return nil, ErrAlg
 	}
 
 	switch k.Algorithm {
-	case DSA, DSANSEC3SHA1:
-		params := new(dsa.Parameters)
-		if err := dsa.GenerateParameters(params, rand.Reader, dsa.L1024N160); err != nil {
-			return nil, err
-		}
-		priv := new(dsa.PrivateKey)
-		priv.PublicKey.Parameters = *params
-		err := dsa.GenerateKey(priv, rand.Reader)
-		if err != nil {
-			return nil, err
-		}
-		k.setPublicKeyDSA(params.Q, params.P, params.G, priv.PublicKey.Y)
-		return priv, nil
-	case RSAMD5, RSASHA1, RSASHA256, RSASHA512, RSASHA1NSEC3SHA1:
+	case RSASHA1, RSASHA256, RSASHA512, RSASHA1NSEC3SHA1:
 		priv, err := rsa.GenerateKey(rand.Reader, bits)
 		if err != nil {
 			return nil, err
@@ -75,6 +64,13 @@ func (k *DNSKEY) Generate(bits int) (crypto.PrivateKey, error) {
 		}
 		k.setPublicKeyECDSA(priv.PublicKey.X, priv.PublicKey.Y)
 		return priv, nil
+	case ED25519:
+		pub, priv, err := ed25519.GenerateKey(rand.Reader)
+		if err != nil {
+			return nil, err
+		}
+		k.setPublicKeyED25519(pub)
+		return priv, nil
 	default:
 		return nil, ErrAlg
 	}
@@ -107,13 +103,12 @@ func (k *DNSKEY) setPublicKeyECDSA(_X, _Y *big.Int) bool {
 	return true
 }
 
-// Set the public key for DSA
-func (k *DNSKEY) setPublicKeyDSA(_Q, _P, _G, _Y *big.Int) bool {
-	if _Q == nil || _P == nil || _G == nil || _Y == nil {
+// Set the public key for Ed25519
+func (k *DNSKEY) setPublicKeyED25519(_K ed25519.PublicKey) bool {
+	if _K == nil {
 		return false
 	}
-	buf := dsaToBuf(_Q, _P, _G, _Y)
-	k.PublicKey = toBase64(buf)
+	k.PublicKey = toBase64(_K)
 	return true
 }
 
@@ -121,17 +116,17 @@ func (k *DNSKEY) setPublicKeyDSA(_Q, _P, _G, _Y *big.Int) bool {
 // RFC 3110: Section 2. RSA Public KEY Resource Records
 func exponentToBuf(_E int) []byte {
 	var buf []byte
-	i := big.NewInt(int64(_E))
-	if len(i.Bytes()) < 256 {
-		buf = make([]byte, 1)
-		buf[0] = uint8(len(i.Bytes()))
+	i := big.NewInt(int64(_E)).Bytes()
+	if len(i) < 256 {
+		buf = make([]byte, 1, 1+len(i))
+		buf[0] = uint8(len(i))
 	} else {
-		buf = make([]byte, 3)
+		buf = make([]byte, 3, 3+len(i))
 		buf[0] = 0
-		buf[1] = uint8(len(i.Bytes()) >> 8)
-		buf[2] = uint8(len(i.Bytes()))
+		buf[1] = uint8(len(i) >> 8)
+		buf[2] = uint8(len(i))
 	}
-	buf = append(buf, i.Bytes()...)
+	buf = append(buf, i...)
 	return buf
 }
 
@@ -142,15 +137,3 @@ func curveToBuf(_X, _Y *big.Int, intlen int) []byte {
 	buf = append(buf, intToBytes(_Y, intlen)...)
 	return buf
 }
-
-// Set the public key for X and Y for Curve. The two
-// values are just concatenated.
-func dsaToBuf(_Q, _P, _G, _Y *big.Int) []byte {
-	t := divRoundUp(divRoundUp(_G.BitLen(), 8)-64, 8)
-	buf := []byte{byte(t)}
-	buf = append(buf, intToBytes(_Q, 20)...)
-	buf = append(buf, intToBytes(_P, 64+t*8)...)
-	buf = append(buf, intToBytes(_G, 64+t*8)...)
-	buf = append(buf, intToBytes(_Y, 64+t*8)...)
-	return buf
-}

vendor/github.com/miekg/dns/dnssec_keyscan.go

 package dns
 
 import (
+	"bufio"
 	"crypto"
-	"crypto/dsa"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/rsa"
 	"io"
 	"math/big"
@@ -14,7 +15,7 @@ import (
 // NewPrivateKey returns a PrivateKey by parsing the string s.
 // s should be in the same form of the BIND private key files.
 func (k *DNSKEY) NewPrivateKey(s string) (crypto.PrivateKey, error) {
-	if s[len(s)-1] != '\n' { // We need a closing newline
+	if s == "" || s[len(s)-1] != '\n' { // We need a closing newline
 		return k.ReadPrivateKey(strings.NewReader(s+"\n"), "")
 	}
 	return k.ReadPrivateKey(strings.NewReader(s), "")
@@ -25,9 +26,9 @@ func (k *DNSKEY) NewPrivateKey(s string) (crypto.PrivateKey, error) {
 // The public key must be known, because some cryptographic algorithms embed
 // the public inside the privatekey.
 func (k *DNSKEY) ReadPrivateKey(q io.Reader, file string) (crypto.PrivateKey, error) {
-	m, e := parseKey(q, file)
+	m, err := parseKey(q, file)
 	if m == nil {
-		return nil, e
+		return nil, err
 	}
 	if _, ok := m["private-key-format"]; !ok {
 		return nil, ErrPrivKey
@@ -36,58 +37,37 @@ func (k *DNSKEY) ReadPrivateKey(q io.Reader, file string) (crypto.PrivateKey, er
 		return nil, ErrPrivKey
 	}
 	// TODO(mg): check if the pubkey matches the private key
-	algo, err := strconv.Atoi(strings.SplitN(m["algorithm"], " ", 2)[0])
+	algo, err := strconv.ParseUint(strings.SplitN(m["algorithm"], " ", 2)[0], 10, 8)
 	if err != nil {
 		return nil, ErrPrivKey
 	}
 	switch uint8(algo) {
-	case DSA:
-		priv, e := readPrivateKeyDSA(m)
-		if e != nil {
-			return nil, e
-		}
-		pub := k.publicKeyDSA()
-		if pub == nil {
-			return nil, ErrKey
-		}
-		priv.PublicKey = *pub
-		return priv, e
-	case RSAMD5:
-		fallthrough
-	case RSASHA1:
-		fallthrough
-	case RSASHA1NSEC3SHA1:
-		fallthrough
-	case RSASHA256:
-		fallthrough
-	case RSASHA512:
-		priv, e := readPrivateKeyRSA(m)
-		if e != nil {
-			return nil, e
+	case RSASHA1, RSASHA1NSEC3SHA1, RSASHA256, RSASHA512:
+		priv, err := readPrivateKeyRSA(m)
+		if err != nil {
+			return nil, err
 		}
 		pub := k.publicKeyRSA()
 		if pub == nil {
 			return nil, ErrKey
 		}
 		priv.PublicKey = *pub
-		return priv, e
-	case ECCGOST:
-		return nil, ErrPrivKey
-	case ECDSAP256SHA256:
-		fallthrough
-	case ECDSAP384SHA384:
-		priv, e := readPrivateKeyECDSA(m)
-		if e != nil {
-			return nil, e
+		return priv, nil
+	case ECDSAP256SHA256, ECDSAP384SHA384:
+		priv, err := readPrivateKeyECDSA(m)
+		if err != nil {
+			return nil, err
 		}
 		pub := k.publicKeyECDSA()
 		if pub == nil {
 			return nil, ErrKey
 		}
 		priv.PublicKey = *pub
-		return priv, e
+		return priv, nil
+	case ED25519:
+		return readPrivateKeyED25519(m)
 	default:
-		return nil, ErrPrivKey
+		return nil, ErrAlg
 	}
 }
 
@@ -104,21 +84,16 @@ func readPrivateKeyRSA(m map[string]string) (*rsa.PrivateKey, error) {
 			}
 			switch k {
 			case "modulus":
-				p.PublicKey.N = big.NewInt(0)
-				p.PublicKey.N.SetBytes(v1)
+				p.PublicKey.N = new(big.Int).SetBytes(v1)
 			case "publicexponent":
-				i := big.NewInt(0)
-				i.SetBytes(v1)
+				i := new(big.Int).SetBytes(v1)
 				p.PublicKey.E = int(i.Int64()) // int64 should be large enough
 			case "privateexponent":
-				p.D = big.NewInt(0)
-				p.D.SetBytes(v1)
+				p.D = new(big.Int).SetBytes(v1)
 			case "prime1":
-				p.Primes[0] = big.NewInt(0)
-				p.Primes[0].SetBytes(v1)
+				p.Primes[0] = new(big.Int).SetBytes(v1)
 			case "prime2":
-				p.Primes[1] = big.NewInt(0)
-				p.Primes[1].SetBytes(v1)
+				p.Primes[1] = new(big.Int).SetBytes(v1)
 			}
 		case "exponent1", "exponent2", "coefficient":
 			// not used in Go (yet)
@@ -129,17 +104,18 @@ func readPrivateKeyRSA(m map[string]string) (*rsa.PrivateKey, error) {
 	return p, nil
 }
 
-func readPrivateKeyDSA(m map[string]string) (*dsa.PrivateKey, error) {
-	p := new(dsa.PrivateKey)
-	p.X = big.NewInt(0)
+func readPrivateKeyECDSA(m map[string]string) (*ecdsa.PrivateKey, error) {
+	p := new(ecdsa.PrivateKey)
+	p.D = new(big.Int)
+	// TODO: validate that the required flags are present
 	for k, v := range m {
 		switch k {
-		case "private_value(x)":
+		case "privatekey":
 			v1, err := fromBase64([]byte(v))
 			if err != nil {
 				return nil, err
 			}
-			p.X.SetBytes(v1)
+			p.D.SetBytes(v1)
 		case "created", "publish", "activate":
 			/* not used in Go (yet) */
 		}
@@ -147,18 +123,20 @@ func readPrivateKeyDSA(m map[string]string) (*dsa.PrivateKey, error) {
 	return p, nil
 }
 
-func readPrivateKeyECDSA(m map[string]string) (*ecdsa.PrivateKey, error) {
-	p := new(ecdsa.PrivateKey)
-	p.D = big.NewInt(0)
+func readPrivateKeyED25519(m map[string]string) (ed25519.PrivateKey, error) {
+	var p ed25519.PrivateKey
 	// TODO: validate that the required flags are present
 	for k, v := range m {
 		switch k {
 		case "privatekey":
-			v1, err := fromBase64([]byte(v))
+			p1, err := fromBase64([]byte(v))
 			if err != nil {
 				return nil, err
 			}
-			p.D.SetBytes(v1)
+			if len(p1) != ed25519.SeedSize {
+				return nil, ErrPrivKey
+			}
+			p = ed25519.NewKeyFromSeed(p1)
 		case "created", "publish", "activate":
 			/* not used in Go (yet) */
 		}
@@ -169,13 +147,12 @@ func readPrivateKeyECDSA(m map[string]string) (*ecdsa.PrivateKey, error) {
 // parseKey reads a private key from r. It returns a map[string]string,
 // with the key-value pairs, or an error when the file is not correct.
 func parseKey(r io.Reader, file string) (map[string]string, error) {
-	s := scanInit(r)
 	m := make(map[string]string)
-	c := make(chan lex)
-	k := ""
-	// Start the lexer
-	go klexer(s, c)
-	for l := range c {
+	var k string
+
+	c := newKLexer(r)
+
+	for l, ok := c.Next(); ok; l, ok = c.Next() {
 		// It should alternate
 		switch l.value {
 		case zKey:
@@ -184,41 +161,111 @@ func parseKey(r io.Reader, file string) (map[string]string, error) {
 			if k == "" {
 				return nil, &ParseError{file, "no private key seen", l}
 			}
-			//println("Setting", strings.ToLower(k), "to", l.token, "b")
+
 			m[strings.ToLower(k)] = l.token
 			k = ""
 		}
 	}
+
+	// Surface any read errors from r.
+	if err := c.Err(); err != nil {
+		return nil, &ParseError{file: file, err: err.Error()}
+	}
+
 	return m, nil
 }
 
-// klexer scans the sourcefile and returns tokens on the channel c.
-func klexer(s *scan, c chan lex) {
-	var l lex
-	str := "" // Hold the current read text
-	commt := false
-	key := true
-	x, err := s.tokenText()
-	defer close(c)
-	for err == nil {
-		l.column = s.position.Column
-		l.line = s.position.Line
+type klexer struct {
+	br io.ByteReader
+
+	readErr error
+
+	line   int
+	column int
+
+	key bool
+
+	eol bool // end-of-line
+}
+
+func newKLexer(r io.Reader) *klexer {
+	br, ok := r.(io.ByteReader)
+	if !ok {
+		br = bufio.NewReaderSize(r, 1024)
+	}
+
+	return &klexer{
+		br: br,
+
+		line: 1,
+
+		key: true,
+	}
+}
+
+func (kl *klexer) Err() error {
+	if kl.readErr == io.EOF {
+		return nil
+	}
+
+	return kl.readErr
+}
+
+// readByte returns the next byte from the input
+func (kl *klexer) readByte() (byte, bool) {
+	if kl.readErr != nil {
+		return 0, false
+	}
+
+	c, err := kl.br.ReadByte()
+	if err != nil {
+		kl.readErr = err
+		return 0, false
+	}
+
+	// delay the newline handling until the next token is delivered,
+	// fixes off-by-one errors when reporting a parse error.
+	if kl.eol {
+		kl.line++
+		kl.column = 0
+		kl.eol = false
+	}
+
+	if c == '\n' {
+		kl.eol = true
+	} else {
+		kl.column++
+	}
+
+	return c, true
+}
+
+func (kl *klexer) Next() (lex, bool) {
+	var (
+		l lex
+
+		str strings.Builder
+
+		commt bool
+	)
+
+	for x, ok := kl.readByte(); ok; x, ok = kl.readByte() {
+		l.line, l.column = kl.line, kl.column
+
 		switch x {
 		case ':':
-			if commt {
+			if commt || !kl.key {
 				break
 			}
-			l.token = str
-			if key {
-				l.value = zKey
-				c <- l
-				// Next token is a space, eat it
-				s.tokenText()
-				key = false
-				str = ""
-			} else {
-				l.value = zValue
-			}
+
+			kl.key = false
+
+			// Next token is a space, eat it
+			kl.readByte()
+
+			l.value = zKey
+			l.token = str.String()
+			return l, true
 		case ';':
 			commt = true
 		case '\n':
@@ -226,24 +273,37 @@ func klexer(s *scan, c chan lex) {
 				// Reset a comment
 				commt = false
 			}
+
+			if kl.key && str.Len() == 0 {
+				// ignore empty lines
+				break
+			}
+
+			kl.key = true
+
 			l.value = zValue
-			l.token = str
-			c <- l
-			str = ""
-			commt = false
-			key = true
+			l.token = str.String()
+			return l, true
 		default:
 			if commt {
 				break
 			}
-			str += string(x)
+
+			str.WriteByte(x)
 		}
-		x, err = s.tokenText()
 	}
-	if len(str) > 0 {
+
+	if kl.readErr != nil && kl.readErr != io.EOF {
+		// Don't return any tokens after a read error occurs.
+		return lex{value: zEOF}, false
+	}
+
+	if str.Len() > 0 {
 		// Send remainder
-		l.token = str
 		l.value = zValue
-		c <- l
+		l.token = str.String()
+		return l, true
 	}
+
+	return lex{value: zEOF}, false
 }

vendor/github.com/miekg/dns/dnssec_privkey.go

@@ -2,8 +2,8 @@ package dns
 
 import (
 	"crypto"
-	"crypto/dsa"
 	"crypto/ecdsa"
+	"crypto/ed25519"
 	"crypto/rsa"
 	"math/big"
 	"strconv"
@@ -11,10 +11,12 @@ import (
 
 const format = "Private-key-format: v1.3\n"
 
+var bigIntOne = big.NewInt(1)
+
 // PrivateKeyString converts a PrivateKey to a string. This string has the same
 // format as the private-key-file of BIND9 (Private-key-format: v1.3).
-// It needs some info from the key (the algorithm), so its a method of the DNSKEY
-// It supports rsa.PrivateKey, ecdsa.PrivateKey and dsa.PrivateKey
+// It needs some info from the key (the algorithm), so its a method of the DNSKEY.
+// It supports *rsa.PrivateKey, *ecdsa.PrivateKey and ed25519.PrivateKey.
 func (r *DNSKEY) PrivateKeyString(p crypto.PrivateKey) string {
 	algorithm := strconv.Itoa(int(r.Algorithm))
 	algorithm += " (" + AlgorithmToString[r.Algorithm] + ")"
@@ -29,12 +31,11 @@ func (r *DNSKEY) PrivateKeyString(p crypto.PrivateKey) string {
 		prime2 := toBase64(p.Primes[1].Bytes())
 		// Calculate Exponent1/2 and Coefficient as per: http://en.wikipedia.org/wiki/RSA#Using_the_Chinese_remainder_algorithm
 		// and from: http://code.google.com/p/go/issues/detail?id=987
-		one := big.NewInt(1)
-		p1 := big.NewInt(0).Sub(p.Primes[0], one)
-		q1 := big.NewInt(0).Sub(p.Primes[1], one)
-		exp1 := big.NewInt(0).Mod(p.D, p1)
-		exp2 := big.NewInt(0).Mod(p.D, q1)
-		coeff := big.NewInt(0).ModInverse(p.Primes[1], p.Primes[0])
+		p1 := new(big.Int).Sub(p.Primes[0], bigIntOne)
+		q1 := new(big.Int).Sub(p.Primes[1], bigIntOne)
+		exp1 := new(big.Int).Mod(p.D, p1)
+		exp2 := new(big.Int).Mod(p.D, q1)
+		coeff := new(big.Int).ModInverse(p.Primes[1], p.Primes[0])
 
 		exponent1 := toBase64(exp1.Bytes())
 		exponent2 := toBase64(exp2.Bytes())
@@ -64,20 +65,11 @@ func (r *DNSKEY) PrivateKeyString(p crypto.PrivateKey) string {
 			"Algorithm: " + algorithm + "\n" +
 			"PrivateKey: " + private + "\n"
 
-	case *dsa.PrivateKey:
-		T := divRoundUp(divRoundUp(p.PublicKey.Parameters.G.BitLen(), 8)-64, 8)
-		prime := toBase64(intToBytes(p.PublicKey.Parameters.P, 64+T*8))
-		subprime := toBase64(intToBytes(p.PublicKey.Parameters.Q, 20))
-		base := toBase64(intToBytes(p.PublicKey.Parameters.G, 64+T*8))
-		priv := toBase64(intToBytes(p.X, 20))
-		pub := toBase64(intToBytes(p.PublicKey.Y, 64+T*8))
+	case ed25519.PrivateKey:
+		private := toBase64(p.Seed())
 		return format +
 			"Algorithm: " + algorithm + "\n" +
-			"Prime(p): " + prime + "\n" +
-			"Subprime(q): " + subprime + "\n" +
-			"Base(g): " + base + "\n" +
-			"Private_value(x): " + priv + "\n" +
-			"Public_value(y): " + pub + "\n"
+			"PrivateKey: " + private + "\n"
 
 	default:
 		return ""

vendor/github.com/miekg/dns/doc.go

 /*
 Package dns implements a full featured interface to the Domain Name System.
-Server- and client-side programming is supported.
-The package allows complete control over what is send out to the DNS. The package
-API follows the less-is-more principle, by presenting a small, clean interface.
+Both server- and client-side programming is supported. The package allows
+complete control over what is sent out to the DNS. The API follows the
+less-is-more principle, by presenting a small, clean interface.
 
-The package dns supports (asynchronous) querying/replying, incoming/outgoing zone transfers,
+It supports (asynchronous) querying/replying, incoming/outgoing zone transfers,
 TSIG, EDNS0, dynamic updates, notifies and DNSSEC validation/signing.
-Note that domain names MUST be fully qualified, before sending them, unqualified
+
+Note that domain names MUST be fully qualified before sending them, unqualified
 names in a message will result in a packing failure.
 
-Resource records are native types. They are not stored in wire format.
-Basic usage pattern for creating a new resource record:
+Resource records are native types. They are not stored in wire format. Basic
+usage pattern for creating a new resource record:
 
      r := new(dns.MX)
-     r.Hdr = dns.RR_Header{Name: "miek.nl.", Rrtype: dns.TypeMX,
-	Class: dns.ClassINET, Ttl: 3600}
+     r.Hdr = dns.RR_Header{Name: "miek.nl.", Rrtype: dns.TypeMX, Class: dns.ClassINET, Ttl: 3600}
      r.Preference = 10
      r.Mx = "mx.miek.nl."
 
@@ -22,16 +22,16 @@ Or directly from a string:
 
      mx, err := dns.NewRR("miek.nl. 3600 IN MX 10 mx.miek.nl.")
 
-Or when the default TTL (3600) and class (IN) suit you:
+Or when the default origin (.) and TTL (3600) and class (IN) suit you:
 
-     mx, err := dns.NewRR("miek.nl. MX 10 mx.miek.nl.")
+     mx, err := dns.NewRR("miek.nl MX 10 mx.miek.nl")
 
 Or even:
 
      mx, err := dns.NewRR("$ORIGIN nl.\nmiek 1H IN MX 10 mx.miek")
 
-In the DNS messages are exchanged, these messages contain resource
-records (sets).  Use pattern for creating a message:
+In the DNS messages are exchanged, these messages contain resource records
+(sets). Use pattern for creating a message:
 
      m := new(dns.Msg)
      m.SetQuestion("miek.nl.", dns.TypeMX)
@@ -40,8 +40,8 @@ Or when not certain if the domain name is fully qualified:
 
 	m.SetQuestion(dns.Fqdn("miek.nl"), dns.TypeMX)
 
-The message m is now a message with the question section set to ask
-the MX records for the miek.nl. zone.
+The message m is now a message with the question section set to ask the MX
+records for the miek.nl. zone.
 
 The following is slightly more verbose, but more flexible:
 
@@ -51,9 +51,8 @@ The following is slightly more verbose, but more flexible:
      m1.Question = make([]dns.Question, 1)
      m1.Question[0] = dns.Question{"miek.nl.", dns.TypeMX, dns.ClassINET}
 
-After creating a message it can be send.
-Basic use pattern for synchronous querying the DNS at a
-server configured on 127.0.0.1 and port 53:
+After creating a message it can be sent. Basic use pattern for synchronous
+querying the DNS at a server configured on 127.0.0.1 and port 53:
 
      c := new(dns.Client)
      in, rtt, err := c.Exchange(m1, "127.0.0.1:53")
@@ -63,12 +62,28 @@ class) is as easy as setting:
 
 	c.SingleInflight = true
 
-If these "advanced" features are not needed, a simple UDP query can be send,
+More advanced options are available using a net.Dialer and the corresponding API.
+For example it is possible to set a timeout, or to specify a source IP address
+and port to use for the connection:
+
+	c := new(dns.Client)
+	laddr := net.UDPAddr{
+		IP: net.ParseIP("[::1]"),
+		Port: 12345,
+		Zone: "",
+	}
+	c.Dialer := &net.Dialer{
+		Timeout: 200 * time.Millisecond,
+		LocalAddr: &laddr,
+	}
+	in, rtt, err := c.Exchange(m1, "8.8.8.8:53")
+
+If these "advanced" features are not needed, a simple UDP query can be sent,
 with:
 
 	in, err := dns.Exchange(m1, "127.0.0.1:53")
 
-When this functions returns you will get dns message. A dns message consists
+When this functions returns you will get DNS message. A DNS message consists
 out of four sections.
 The question section: in.Question, the answer section: in.Answer,
 the authority section: in.Ns and the additional section: in.Extra.
@@ -83,25 +98,24 @@ the Answer section:
 
 Domain Name and TXT Character String Representations
 
-Both domain names and TXT character strings are converted to presentation
-form both when unpacked and when converted to strings.
+Both domain names and TXT character strings are converted to presentation form
+both when unpacked and when converted to strings.
 
 For TXT character strings, tabs, carriage returns and line feeds will be
-converted to \t, \r and \n respectively. Back slashes and quotations marks
-will be escaped. Bytes below 32 and above 127 will be converted to \DDD
-form.
+converted to \t, \r and \n respectively. Back slashes and quotations marks will
+be escaped. Bytes below 32 and above 127 will be converted to \DDD form.
 
-For domain names, in addition to the above rules brackets, periods,
-spaces, semicolons and the at symbol are escaped.
+For domain names, in addition to the above rules brackets, periods, spaces,
+semicolons and the at symbol are escaped.
 
 DNSSEC
 
-DNSSEC (DNS Security Extension) adds a layer of security to the DNS. It
-uses public key cryptography to sign resource records. The
-public keys are stored in DNSKEY records and the signatures in RRSIG records.
+DNSSEC (DNS Security Extension) adds a layer of security to the DNS. It uses
+public key cryptography to sign resource records. The public keys are stored in
+DNSKEY records and the signatures in RRSIG records.
 
-Requesting DNSSEC information for a zone is done by adding the DO (DNSSEC OK) bit
-to an request.
+Requesting DNSSEC information for a zone is done by adding the DO (DNSSEC OK)
+bit to a request.
 
      m := new(dns.Msg)
      m.SetEdns0(4096, true)
@@ -110,9 +124,9 @@ Signature generation, signature verification and key generation are all supporte
 
 DYNAMIC UPDATES
 
-Dynamic updates reuses the DNS message format, but renames three of
-the sections. Question is Zone, Answer is Prerequisite, Authority is
-Update, only the Additional is not renamed. See RFC 2136 for the gory details.
+Dynamic updates reuses the DNS message format, but renames three of the
+sections. Question is Zone, Answer is Prerequisite, Authority is Update, only
+the Additional is not renamed. See RFC 2136 for the gory details.
 
 You can set a rather complex set of rules for the existence of absence of
 certain resource records or names in a zone to specify if resource records
@@ -129,10 +143,9 @@ DNS function shows which functions exist to specify the prerequisites.
   NONE     rrset    empty    RRset does not exist       dns.RRsetNotUsed
   zone     rrset    rr       RRset exists (value dep)   dns.Used
 
-The prerequisite section can also be left empty.
-If you have decided on the prerequisites you can tell what RRs should
-be added or deleted. The next table shows the options you have and
-what functions to call.
+The prerequisite section can also be left empty. If you have decided on the
+prerequisites you can tell what RRs should be added or deleted. The next table
+shows the options you have and what functions to call.
 
  3.4.2.6 - Table Of Metavalues Used In Update Section
 
@@ -146,35 +159,64 @@ what functions to call.
 TRANSACTION SIGNATURE
 
 An TSIG or transaction signature adds a HMAC TSIG record to each message sent.
-The supported algorithms include: HmacMD5, HmacSHA1, HmacSHA256 and HmacSHA512.
+The supported algorithms include: HmacSHA1, HmacSHA256 and HmacSHA512.
 
 Basic use pattern when querying with a TSIG name "axfr." (note that these key names
 must be fully qualified - as they are domain names) and the base64 secret
 "so6ZGir4GPAqINNh9U5c3A==":
 
+If an incoming message contains a TSIG record it MUST be the last record in
+the additional section (RFC2845 3.2).  This means that you should make the
+call to SetTsig last, right before executing the query.  If you make any
+changes to the RRset after calling SetTsig() the signature will be incorrect.
+
 	c := new(dns.Client)
 	c.TsigSecret = map[string]string{"axfr.": "so6ZGir4GPAqINNh9U5c3A=="}
 	m := new(dns.Msg)
 	m.SetQuestion("miek.nl.", dns.TypeMX)
-	m.SetTsig("axfr.", dns.HmacMD5, 300, time.Now().Unix())
+	m.SetTsig("axfr.", dns.HmacSHA256, 300, time.Now().Unix())
 	...
 	// When sending the TSIG RR is calculated and filled in before sending
 
-When requesting an zone transfer (almost all TSIG usage is when requesting zone transfers), with
-TSIG, this is the basic use pattern. In this example we request an AXFR for
-miek.nl. with TSIG key named "axfr." and secret "so6ZGir4GPAqINNh9U5c3A=="
-and using the server 176.58.119.54:
+When requesting an zone transfer (almost all TSIG usage is when requesting zone
+transfers), with TSIG, this is the basic use pattern. In this example we
+request an AXFR for miek.nl. with TSIG key named "axfr." and secret
+"so6ZGir4GPAqINNh9U5c3A==" and using the server 176.58.119.54:
 
 	t := new(dns.Transfer)
 	m := new(dns.Msg)
 	t.TsigSecret = map[string]string{"axfr.": "so6ZGir4GPAqINNh9U5c3A=="}
 	m.SetAxfr("miek.nl.")
-	m.SetTsig("axfr.", dns.HmacMD5, 300, time.Now().Unix())
+	m.SetTsig("axfr.", dns.HmacSHA256, 300, time.Now().Unix())
 	c, err := t.In(m, "176.58.119.54:53")
 	for r := range c { ... }
 
-You can now read the records from the transfer as they come in. Each envelope is checked with TSIG.
-If something is not correct an error is returned.
+You can now read the records from the transfer as they come in. Each envelope
+is checked with TSIG. If something is not correct an error is returned.
+
+A custom TSIG implementation can be used. This requires additional code to
+perform any session establishment and signature generation/verification. The
+client must be configured with an implementation of the TsigProvider interface:
+
+	type Provider struct{}
+
+	func (*Provider) Generate(msg []byte, tsig *dns.TSIG) ([]byte, error) {
+		// Use tsig.Hdr.Name and tsig.Algorithm in your code to
+		// generate the MAC using msg as the payload.
+	}
+
+	func (*Provider) Verify(msg []byte, tsig *dns.TSIG) error {
+		// Use tsig.Hdr.Name and tsig.Algorithm in your code to verify
+		// that msg matches the value in tsig.MAC.
+	}
+
+	c := new(dns.Client)
+	c.TsigProvider = new(Provider)
+	m := new(dns.Msg)
+	m.SetQuestion("miek.nl.", dns.TypeMX)
+	m.SetTsig(keyname, dns.HmacSHA256, 300, time.Now().Unix())
+	...
+	// TSIG RR is calculated by calling your Generate method
 
 Basic use pattern validating and replying to a message that has TSIG set.
 
@@ -186,12 +228,12 @@ Basic use pattern validating and replying to a message that has TSIG set.
 	func handleRequest(w dns.ResponseWriter, r *dns.Msg) {
 		m := new(dns.Msg)
 		m.SetReply(r)
-		if r.IsTsig() {
+		if r.IsTsig() != nil {
 			if w.TsigStatus() == nil {
 				// *Msg r has an TSIG record and it was validated
-				m.SetTsig("axfr.", dns.HmacMD5, 300, time.Now().Unix())
+				m.SetTsig("axfr.", dns.HmacSHA256, 300, time.Now().Unix())
 			} else {
-				// *Msg r has an TSIG records and it was not valided
+				// *Msg r has an TSIG records and it was not validated
 			}
 		}
 		w.WriteMsg(m)
@@ -199,28 +241,28 @@ Basic use pattern validating and replying to a message that has TSIG set.
 
 PRIVATE RRS
 
-RFC 6895 sets aside a range of type codes for private use. This range
-is 65,280 - 65,534 (0xFF00 - 0xFFFE). When experimenting with new Resource Records these
+RFC 6895 sets aside a range of type codes for private use. This range is 65,280
+- 65,534 (0xFF00 - 0xFFFE). When experimenting with new Resource Records these
 can be used, before requesting an official type code from IANA.
 
-see http://miek.nl/posts/2014/Sep/21/Private%20RRs%20and%20IDN%20in%20Go%20DNS/ for more
+See https://miek.nl/2014/september/21/idn-and-private-rr-in-go-dns/ for more
 information.
 
 EDNS0
 
-EDNS0 is an extension mechanism for the DNS defined in RFC 2671 and updated
-by RFC 6891. It defines an new RR type, the OPT RR, which is then completely
+EDNS0 is an extension mechanism for the DNS defined in RFC 2671 and updated by
+RFC 6891. It defines a new RR type, the OPT RR, which is then completely
 abused.
+
 Basic use pattern for creating an (empty) OPT RR:
 
 	o := new(dns.OPT)
 	o.Hdr.Name = "." // MUST be the root zone, per definition.
 	o.Hdr.Rrtype = dns.TypeOPT
 
-The rdata of an OPT RR consists out of a slice of EDNS0 (RFC 6891)
-interfaces. Currently only a few have been standardized: EDNS0_NSID
-(RFC 5001) and EDNS0_SUBNET (draft-vandergaast-edns-client-subnet-02). Note
-that these options may be combined in an OPT RR.
+The rdata of an OPT RR consists out of a slice of EDNS0 (RFC 6891) interfaces.
+Currently only a few have been standardized: EDNS0_NSID (RFC 5001) and
+EDNS0_SUBNET (RFC 7871). Note that these options may be combined in an OPT RR.
 Basic use pattern for a server to check if (and which) options are set:
 
 	// o is a dns.OPT
@@ -241,10 +283,9 @@ From RFC 2931:
     ... protection for glue records, DNS requests, protection for message headers
     on requests and responses, and protection of the overall integrity of a response.
 
-It works like TSIG, except that SIG(0) uses public key cryptography, instead of the shared
-secret approach in TSIG.
-Supported algorithms: DSA, ECDSAP256SHA256, ECDSAP384SHA384, RSASHA1, RSASHA256 and
-RSASHA512.
+It works like TSIG, except that SIG(0) uses public key cryptography, instead of
+the shared secret approach in TSIG. Supported algorithms: ECDSAP256SHA256,
+ECDSAP384SHA384, RSASHA1, RSASHA256 and RSASHA512.
 
 Signing subsequent messages in multi-message sessions is not implemented.
 */

vendor/github.com/miekg/dns/duplicate.go

+package dns
+
+//go:generate go run duplicate_generate.go
+
+// IsDuplicate checks of r1 and r2 are duplicates of each other, excluding the TTL.
+// So this means the header data is equal *and* the RDATA is the same. Returns true
+// if so, otherwise false. It's a protocol violation to have identical RRs in a message.
+func IsDuplicate(r1, r2 RR) bool {
+	// Check whether the record header is identical.
+	if !r1.Header().isDuplicate(r2.Header()) {
+		return false
+	}
+
+	// Check whether the RDATA is identical.
+	return r1.isDuplicate(r2)
+}
+
+func (r1 *RR_Header) isDuplicate(_r2 RR) bool {
+	r2, ok := _r2.(*RR_Header)
+	if !ok {
+		return false
+	}
+	if r1.Class != r2.Class {
+		return false
+	}
+	if r1.Rrtype != r2.Rrtype {
+		return false
+	}
+	if !isDuplicateName(r1.Name, r2.Name) {
+		return false
+	}
+	// ignore TTL
+	return true
+}
+
+// isDuplicateName checks if the domain names s1 and s2 are equal.
+func isDuplicateName(s1, s2 string) bool { return equal(s1, s2) }

vendor/github.com/miekg/dns/edns.go

 package dns
 
 import (
+	"encoding/binary"
 	"encoding/hex"
 	"errors"
+	"fmt"
 	"net"
 	"strconv"
 )
 
 // EDNS0 Option codes.
 const (
-	EDNS0LLQ         = 0x1     // long lived queries: http://tools.ietf.org/html/draft-sekar-dns-llq-01
-	EDNS0UL          = 0x2     // update lease draft: http://files.dns-sd.org/draft-sekar-dns-ul.txt
-	EDNS0NSID        = 0x3     // nsid (RFC5001)
-	EDNS0DAU         = 0x5     // DNSSEC Algorithm Understood
-	EDNS0DHU         = 0x6     // DS Hash Understood
-	EDNS0N3U         = 0x7     // NSEC3 Hash Understood
-	EDNS0SUBNET      = 0x8     // client-subnet (RFC6891)
-	EDNS0EXPIRE      = 0x9     // EDNS0 expire
-	EDNS0SUBNETDRAFT = 0x50fa  // Don't use! Use EDNS0SUBNET
-	EDNS0LOCALSTART  = 0xFDE9  // Beginning of range reserved for local/experimental use (RFC6891)
-	EDNS0LOCALEND    = 0xFFFE  // End of range reserved for local/experimental use (RFC6891)
-	_DO              = 1 << 15 // dnssec ok
+	EDNS0LLQ          = 0x1     // long lived queries: http://tools.ietf.org/html/draft-sekar-dns-llq-01
+	EDNS0UL           = 0x2     // update lease draft: http://files.dns-sd.org/draft-sekar-dns-ul.txt
+	EDNS0NSID         = 0x3     // nsid (See RFC 5001)
+	EDNS0ESU          = 0x4     // ENUM Source-URI draft: https://datatracker.ietf.org/doc/html/draft-kaplan-enum-source-uri-00
+	EDNS0DAU          = 0x5     // DNSSEC Algorithm Understood
+	EDNS0DHU          = 0x6     // DS Hash Understood
+	EDNS0N3U          = 0x7     // NSEC3 Hash Understood
+	EDNS0SUBNET       = 0x8     // client-subnet (See RFC 7871)
+	EDNS0EXPIRE       = 0x9     // EDNS0 expire
+	EDNS0COOKIE       = 0xa     // EDNS0 Cookie
+	EDNS0TCPKEEPALIVE = 0xb     // EDNS0 tcp keep alive (See RFC 7828)
+	EDNS0PADDING      = 0xc     // EDNS0 padding (See RFC 7830)
+	EDNS0EDE          = 0xf     // EDNS0 extended DNS errors (See RFC 8914)
+	EDNS0LOCALSTART   = 0xFDE9  // Beginning of range reserved for local/experimental use (See RFC 6891)
+	EDNS0LOCALEND     = 0xFFFE  // End of range reserved for local/experimental use (See RFC 6891)
+	_DO               = 1 << 15 // DNSSEC OK
 )
 
+// makeDataOpt is used to unpack the EDNS0 option(s) from a message.
+func makeDataOpt(code uint16) EDNS0 {
+	// All the EDNS0.* constants above need to be in this switch.
+	switch code {
+	case EDNS0LLQ:
+		return new(EDNS0_LLQ)
+	case EDNS0UL:
+		return new(EDNS0_UL)
+	case EDNS0NSID:
+		return new(EDNS0_NSID)
+	case EDNS0DAU:
+		return new(EDNS0_DAU)
+	case EDNS0DHU:
+		return new(EDNS0_DHU)
+	case EDNS0N3U:
+		return new(EDNS0_N3U)
+	case EDNS0SUBNET:
+		return new(EDNS0_SUBNET)
+	case EDNS0EXPIRE:
+		return new(EDNS0_EXPIRE)
+	case EDNS0COOKIE:
+		return new(EDNS0_COOKIE)
+	case EDNS0TCPKEEPALIVE:
+		return new(EDNS0_TCP_KEEPALIVE)
+	case EDNS0PADDING:
+		return new(EDNS0_PADDING)
+	case EDNS0EDE:
+		return new(EDNS0_EDE)
+	case EDNS0ESU:
+		return &EDNS0_ESU{Code: EDNS0ESU}
+	default:
+		e := new(EDNS0_LOCAL)
+		e.Code = code
+		return e
+	}
+}
+
 // OPT is the EDNS0 RR appended to messages to convey extra (meta) information.
 // See RFC 6891.
 type OPT struct {
@@ -30,11 +73,6 @@ type OPT struct {
 	Option []EDNS0 `dns:"opt"`
 }
 
-// Header implements the RR interface.
-func (rr *OPT) Header() *RR_Header {
-	return &rr.Hdr
-}
-
 func (rr *OPT) String() string {
 	s := "\n;; OPT PSEUDOSECTION:\n; EDNS: version " + strconv.Itoa(int(rr.Version())) + "; "
 	if rr.Do() {
@@ -58,9 +96,10 @@ func (rr *OPT) String() string {
 			}
 		case *EDNS0_SUBNET:
 			s += "\n; SUBNET: " + o.String()
-			if o.(*EDNS0_SUBNET).DraftOption {
-				s += " (draft)"
-			}
+		case *EDNS0_COOKIE:
+			s += "\n; COOKIE: " + o.String()
+		case *EDNS0_TCP_KEEPALIVE:
+			s += "\n; KEEPALIVE: " + o.String()
 		case *EDNS0_UL:
 			s += "\n; UPDATE LEASE: " + o.String()
 		case *EDNS0_LLQ:
@@ -73,45 +112,55 @@ func (rr *OPT) String() string {
 			s += "\n; NSEC3 HASH UNDERSTOOD: " + o.String()
 		case *EDNS0_LOCAL:
 			s += "\n; LOCAL OPT: " + o.String()
+		case *EDNS0_PADDING:
+			s += "\n; PADDING: " + o.String()
+		case *EDNS0_EDE:
+			s += "\n; EDE: " + o.String()
+		case *EDNS0_ESU:
+			s += "\n; ESU: " + o.String()
 		}
 	}
 	return s
 }
 
-func (rr *OPT) len() int {
-	l := rr.Hdr.len()
-	for i := 0; i < len(rr.Option); i++ {
+func (rr *OPT) len(off int, compression map[string]struct{}) int {
+	l := rr.Hdr.len(off, compression)
+	for _, o := range rr.Option {
 		l += 4 // Account for 2-byte option code and 2-byte option length.
-		lo, _ := rr.Option[i].pack()
+		lo, _ := o.pack()
 		l += len(lo)
 	}
 	return l
 }
 
-func (rr *OPT) copy() RR {
-	return &OPT{*rr.Hdr.copyHeader(), rr.Option}
+func (*OPT) parse(c *zlexer, origin string) *ParseError {
+	return &ParseError{err: "OPT records do not have a presentation format"}
 }
 
+func (rr *OPT) isDuplicate(r2 RR) bool { return false }
+
 // return the old value -> delete SetVersion?
 
 // Version returns the EDNS version used. Only zero is defined.
 func (rr *OPT) Version() uint8 {
-	return uint8((rr.Hdr.Ttl & 0x00FF0000) >> 16)
+	return uint8(rr.Hdr.Ttl & 0x00FF0000 >> 16)
 }
 
 // SetVersion sets the version of EDNS. This is usually zero.
 func (rr *OPT) SetVersion(v uint8) {
-	rr.Hdr.Ttl = rr.Hdr.Ttl&0xFF00FFFF | (uint32(v) << 16)
+	rr.Hdr.Ttl = rr.Hdr.Ttl&0xFF00FFFF | uint32(v)<<16
 }
 
 // ExtendedRcode returns the EDNS extended RCODE field (the upper 8 bits of the TTL).
-func (rr *OPT) ExtendedRcode() uint8 {
-	return uint8((rr.Hdr.Ttl & 0xFF000000) >> 24)
+func (rr *OPT) ExtendedRcode() int {
+	return int(rr.Hdr.Ttl&0xFF000000>>24) << 4
 }
 
 // SetExtendedRcode sets the EDNS extended RCODE field.
-func (rr *OPT) SetExtendedRcode(v uint8) {
-	rr.Hdr.Ttl = rr.Hdr.Ttl&0x00FFFFFF | (uint32(v) << 24)
+//
+// If the RCODE is not an extended RCODE, will reset the extended RCODE field to 0.
+func (rr *OPT) SetExtendedRcode(v uint16) {
+	rr.Hdr.Ttl = rr.Hdr.Ttl&0x00FFFFFF | uint32(v>>4)<<24
 }
 
 // UDPSize returns the UDP buffer size.
@@ -130,12 +179,31 @@ func (rr *OPT) Do() bool {
 }
 
 // SetDo sets the DO (DNSSEC OK) bit.
-func (rr *OPT) SetDo() {
-	rr.Hdr.Ttl |= _DO
+// If we pass an argument, set the DO bit to that value.
+// It is possible to pass 2 or more arguments. Any arguments after the 1st is silently ignored.
+func (rr *OPT) SetDo(do ...bool) {
+	if len(do) == 1 {
+		if do[0] {
+			rr.Hdr.Ttl |= _DO
+		} else {
+			rr.Hdr.Ttl &^= _DO
+		}
+	} else {
+		rr.Hdr.Ttl |= _DO
+	}
+}
+
+// Z returns the Z part of the OPT RR as a uint16 with only the 15 least significant bits used.
+func (rr *OPT) Z() uint16 {
+	return uint16(rr.Hdr.Ttl & 0x7FFF)
 }
 
-// EDNS0 defines an EDNS0 Option. An OPT RR can have multiple options appended to
-// it.
+// SetZ sets the Z part of the OPT RR, note only the 15 least significant bits of z are used.
+func (rr *OPT) SetZ(z uint16) {
+	rr.Hdr.Ttl = rr.Hdr.Ttl&^0x7FFF | uint32(z&0x7FFF)
+}
+
+// EDNS0 defines an EDNS0 Option. An OPT RR can have multiple options appended to it.
 type EDNS0 interface {
 	// Option returns the option code for the option.
 	Option() uint16
@@ -146,9 +214,11 @@ type EDNS0 interface {
 	unpack([]byte) error
 	// String returns the string representation of the option.
 	String() string
+	// copy returns a deep-copy of the option.
+	copy() EDNS0
 }
 
-// The nsid EDNS0 option is used to retrieve a nameserver
+// EDNS0_NSID option is used to retrieve a nameserver
 // identifier. When sending a request Nsid must be set to the empty string
 // The identifier is an opaque string encoded as hex.
 // Basic use pattern for creating an nsid option:
@@ -173,12 +243,14 @@ func (e *EDNS0_NSID) pack() ([]byte, error) {
 	return h, nil
 }
 
-func (e *EDNS0_NSID) Option() uint16        { return EDNS0NSID }
+// Option implements the EDNS0 interface.
+func (e *EDNS0_NSID) Option() uint16        { return EDNS0NSID } // Option returns the option code.
 func (e *EDNS0_NSID) unpack(b []byte) error { e.Nsid = hex.EncodeToString(b); return nil }
-func (e *EDNS0_NSID) String() string        { return string(e.Nsid) }
+func (e *EDNS0_NSID) String() string        { return e.Nsid }
+func (e *EDNS0_NSID) copy() EDNS0           { return &EDNS0_NSID{e.Code, e.Nsid} }
 
 // EDNS0_SUBNET is the subnet option that is used to give the remote nameserver
-// an idea of where the client lives. It can then give back a different
+// an idea of where the client lives. See RFC 7871. It can then give back a different
 // answer depending on the location or network topology.
 // Basic use pattern for creating an subnet option:
 //
@@ -188,38 +260,38 @@ func (e *EDNS0_NSID) String() string        { return string(e.Nsid) }
 //	e := new(dns.EDNS0_SUBNET)
 //	e.Code = dns.EDNS0SUBNET
 //	e.Family = 1	// 1 for IPv4 source address, 2 for IPv6
-//	e.NetMask = 32	// 32 for IPV4, 128 for IPv6
+//	e.SourceNetmask = 32	// 32 for IPV4, 128 for IPv6
 //	e.SourceScope = 0
 //	e.Address = net.ParseIP("127.0.0.1").To4()	// for IPv4
 //	// e.Address = net.ParseIP("2001:7b8:32a::2")	// for IPV6
 //	o.Option = append(o.Option, e)
 //
-// Note: the spec (draft-ietf-dnsop-edns-client-subnet-00) has some insane logic
-// for which netmask applies to the address. This code will parse all the
-// available bits when unpacking (up to optlen). When packing it will apply
-// SourceNetmask. If you need more advanced logic, patches welcome and good luck.
+// This code will parse all the available bits when unpacking (up to optlen).
+// When packing it will apply SourceNetmask. If you need more advanced logic,
+// patches welcome and good luck.
 type EDNS0_SUBNET struct {
 	Code          uint16 // Always EDNS0SUBNET
 	Family        uint16 // 1 for IP, 2 for IP6
 	SourceNetmask uint8
 	SourceScope   uint8
 	Address       net.IP
-	DraftOption   bool // Set to true if using the old (0x50fa) option code
 }
 
-func (e *EDNS0_SUBNET) Option() uint16 {
-	if e.DraftOption {
-		return EDNS0SUBNETDRAFT
-	}
-	return EDNS0SUBNET
-}
+// Option implements the EDNS0 interface.
+func (e *EDNS0_SUBNET) Option() uint16 { return EDNS0SUBNET }
 
 func (e *EDNS0_SUBNET) pack() ([]byte, error) {
 	b := make([]byte, 4)
-	b[0], b[1] = packUint16(e.Family)
+	binary.BigEndian.PutUint16(b[0:], e.Family)
 	b[2] = e.SourceNetmask
 	b[3] = e.SourceScope
 	switch e.Family {
+	case 0:
+		// "dig" sets AddressFamily to 0 if SourceNetmask is also 0
+		// We might don't need to complain either
+		if e.SourceNetmask != 0 {
+			return nil, errors.New("dns: bad address family")
+		}
 	case 1:
 		if e.SourceNetmask > net.IPv4len*8 {
 			return nil, errors.New("dns: bad netmask")
@@ -250,30 +322,31 @@ func (e *EDNS0_SUBNET) unpack(b []byte) error {
 	if len(b) < 4 {
 		return ErrBuf
 	}
-	e.Family, _ = unpackUint16(b, 0)
+	e.Family = binary.BigEndian.Uint16(b)
 	e.SourceNetmask = b[2]
 	e.SourceScope = b[3]
 	switch e.Family {
+	case 0:
+		// "dig" sets AddressFamily to 0 if SourceNetmask is also 0
+		// It's okay to accept such a packet
+		if e.SourceNetmask != 0 {
+			return errors.New("dns: bad address family")
+		}
+		e.Address = net.IPv4(0, 0, 0, 0)
 	case 1:
 		if e.SourceNetmask > net.IPv4len*8 || e.SourceScope > net.IPv4len*8 {
 			return errors.New("dns: bad netmask")
 		}
-		addr := make([]byte, net.IPv4len)
-		for i := 0; i < net.IPv4len && 4+i < len(b); i++ {
-			addr[i] = b[4+i]
-		}
-		e.Address = net.IPv4(addr[0], addr[1], addr[2], addr[3])
+		addr := make(net.IP, net.IPv4len)
+		copy(addr, b[4:])
+		e.Address = addr.To16()
 	case 2:
 		if e.SourceNetmask > net.IPv6len*8 || e.SourceScope > net.IPv6len*8 {
 			return errors.New("dns: bad netmask")
 		}
-		addr := make([]byte, net.IPv6len)
-		for i := 0; i < net.IPv6len && 4+i < len(b); i++ {
-			addr[i] = b[4+i]
-		}
-		e.Address = net.IP{addr[0], addr[1], addr[2], addr[3], addr[4],
-			addr[5], addr[6], addr[7], addr[8], addr[9], addr[10],
-			addr[11], addr[12], addr[13], addr[14], addr[15]}
+		addr := make(net.IP, net.IPv6len)
+		copy(addr, b[4:])
+		e.Address = addr
 	default:
 		return errors.New("dns: bad address family")
 	}
@@ -292,10 +365,57 @@ func (e *EDNS0_SUBNET) String() (s string) {
 	return
 }
 
+func (e *EDNS0_SUBNET) copy() EDNS0 {
+	return &EDNS0_SUBNET{
+		e.Code,
+		e.Family,
+		e.SourceNetmask,
+		e.SourceScope,
+		e.Address,
+	}
+}
+
+// The EDNS0_COOKIE option is used to add a DNS Cookie to a message.
+//
+//	o := new(dns.OPT)
+//	o.Hdr.Name = "."
+//	o.Hdr.Rrtype = dns.TypeOPT
+//	e := new(dns.EDNS0_COOKIE)
+//	e.Code = dns.EDNS0COOKIE
+//	e.Cookie = "24a5ac.."
+//	o.Option = append(o.Option, e)
+//
+// The Cookie field consists out of a client cookie (RFC 7873 Section 4), that is
+// always 8 bytes. It may then optionally be followed by the server cookie. The server
+// cookie is of variable length, 8 to a maximum of 32 bytes. In other words:
+//
+//	cCookie := o.Cookie[:16]
+//	sCookie := o.Cookie[16:]
+//
+// There is no guarantee that the Cookie string has a specific length.
+type EDNS0_COOKIE struct {
+	Code   uint16 // Always EDNS0COOKIE
+	Cookie string // Hex-encoded cookie data
+}
+
+func (e *EDNS0_COOKIE) pack() ([]byte, error) {
+	h, err := hex.DecodeString(e.Cookie)
+	if err != nil {
+		return nil, err
+	}
+	return h, nil
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_COOKIE) Option() uint16        { return EDNS0COOKIE }
+func (e *EDNS0_COOKIE) unpack(b []byte) error { e.Cookie = hex.EncodeToString(b); return nil }
+func (e *EDNS0_COOKIE) String() string        { return e.Cookie }
+func (e *EDNS0_COOKIE) copy() EDNS0           { return &EDNS0_COOKIE{e.Code, e.Cookie} }
+
 // The EDNS0_UL (Update Lease) (draft RFC) option is used to tell the server to set
 // an expiration on an update RR. This is helpful for clients that cannot clean
 // up after themselves. This is a draft RFC and more information can be found at
-// http://files.dns-sd.org/draft-sekar-dns-ul.txt
+// https://tools.ietf.org/html/draft-sekar-dns-ul-02
 //
 //	o := new(dns.OPT)
 //	o.Hdr.Name = "."
@@ -305,28 +425,39 @@ func (e *EDNS0_SUBNET) String() (s string) {
 //	e.Lease = 120 // in seconds
 //	o.Option = append(o.Option, e)
 type EDNS0_UL struct {
-	Code  uint16 // Always EDNS0UL
-	Lease uint32
+	Code     uint16 // Always EDNS0UL
+	Lease    uint32
+	KeyLease uint32
 }
 
+// Option implements the EDNS0 interface.
 func (e *EDNS0_UL) Option() uint16 { return EDNS0UL }
-func (e *EDNS0_UL) String() string { return strconv.FormatUint(uint64(e.Lease), 10) }
+func (e *EDNS0_UL) String() string { return fmt.Sprintf("%d %d", e.Lease, e.KeyLease) }
+func (e *EDNS0_UL) copy() EDNS0    { return &EDNS0_UL{e.Code, e.Lease, e.KeyLease} }
 
 // Copied: http://golang.org/src/pkg/net/dnsmsg.go
 func (e *EDNS0_UL) pack() ([]byte, error) {
-	b := make([]byte, 4)
-	b[0] = byte(e.Lease >> 24)
-	b[1] = byte(e.Lease >> 16)
-	b[2] = byte(e.Lease >> 8)
-	b[3] = byte(e.Lease)
+	var b []byte
+	if e.KeyLease == 0 {
+		b = make([]byte, 4)
+	} else {
+		b = make([]byte, 8)
+		binary.BigEndian.PutUint32(b[4:], e.KeyLease)
+	}
+	binary.BigEndian.PutUint32(b, e.Lease)
 	return b, nil
 }
 
 func (e *EDNS0_UL) unpack(b []byte) error {
-	if len(b) < 4 {
+	switch len(b) {
+	case 4:
+		e.KeyLease = 0
+	case 8:
+		e.KeyLease = binary.BigEndian.Uint32(b[4:])
+	default:
 		return ErrBuf
 	}
-	e.Lease = uint32(b[0])<<24 | uint32(b[1])<<16 | uint32(b[2])<<8 | uint32(b[3])
+	e.Lease = binary.BigEndian.Uint32(b)
 	return nil
 }
 
@@ -341,25 +472,16 @@ type EDNS0_LLQ struct {
 	LeaseLife uint32
 }
 
+// Option implements the EDNS0 interface.
 func (e *EDNS0_LLQ) Option() uint16 { return EDNS0LLQ }
 
 func (e *EDNS0_LLQ) pack() ([]byte, error) {
 	b := make([]byte, 18)
-	b[0], b[1] = packUint16(e.Version)
-	b[2], b[3] = packUint16(e.Opcode)
-	b[4], b[5] = packUint16(e.Error)
-	b[6] = byte(e.Id >> 56)
-	b[7] = byte(e.Id >> 48)
-	b[8] = byte(e.Id >> 40)
-	b[9] = byte(e.Id >> 32)
-	b[10] = byte(e.Id >> 24)
-	b[11] = byte(e.Id >> 16)
-	b[12] = byte(e.Id >> 8)
-	b[13] = byte(e.Id)
-	b[14] = byte(e.LeaseLife >> 24)
-	b[15] = byte(e.LeaseLife >> 16)
-	b[16] = byte(e.LeaseLife >> 8)
-	b[17] = byte(e.LeaseLife)
+	binary.BigEndian.PutUint16(b[0:], e.Version)
+	binary.BigEndian.PutUint16(b[2:], e.Opcode)
+	binary.BigEndian.PutUint16(b[4:], e.Error)
+	binary.BigEndian.PutUint64(b[6:], e.Id)
+	binary.BigEndian.PutUint32(b[14:], e.LeaseLife)
 	return b, nil
 }
 
@@ -367,69 +489,79 @@ func (e *EDNS0_LLQ) unpack(b []byte) error {
 	if len(b) < 18 {
 		return ErrBuf
 	}
-	e.Version, _ = unpackUint16(b, 0)
-	e.Opcode, _ = unpackUint16(b, 2)
-	e.Error, _ = unpackUint16(b, 4)
-	e.Id = uint64(b[6])<<56 | uint64(b[6+1])<<48 | uint64(b[6+2])<<40 |
-		uint64(b[6+3])<<32 | uint64(b[6+4])<<24 | uint64(b[6+5])<<16 | uint64(b[6+6])<<8 | uint64(b[6+7])
-	e.LeaseLife = uint32(b[14])<<24 | uint32(b[14+1])<<16 | uint32(b[14+2])<<8 | uint32(b[14+3])
+	e.Version = binary.BigEndian.Uint16(b[0:])
+	e.Opcode = binary.BigEndian.Uint16(b[2:])
+	e.Error = binary.BigEndian.Uint16(b[4:])
+	e.Id = binary.BigEndian.Uint64(b[6:])
+	e.LeaseLife = binary.BigEndian.Uint32(b[14:])
 	return nil
 }
 
 func (e *EDNS0_LLQ) String() string {
 	s := strconv.FormatUint(uint64(e.Version), 10) + " " + strconv.FormatUint(uint64(e.Opcode), 10) +
-		" " + strconv.FormatUint(uint64(e.Error), 10) + " " + strconv.FormatUint(uint64(e.Id), 10) +
+		" " + strconv.FormatUint(uint64(e.Error), 10) + " " + strconv.FormatUint(e.Id, 10) +
 		" " + strconv.FormatUint(uint64(e.LeaseLife), 10)
 	return s
 }
+func (e *EDNS0_LLQ) copy() EDNS0 {
+	return &EDNS0_LLQ{e.Code, e.Version, e.Opcode, e.Error, e.Id, e.LeaseLife}
+}
 
+// EDNS0_DAU implements the EDNS0 "DNSSEC Algorithm Understood" option. See RFC 6975.
 type EDNS0_DAU struct {
 	Code    uint16 // Always EDNS0DAU
 	AlgCode []uint8
 }
 
+// Option implements the EDNS0 interface.
 func (e *EDNS0_DAU) Option() uint16        { return EDNS0DAU }
 func (e *EDNS0_DAU) pack() ([]byte, error) { return e.AlgCode, nil }
 func (e *EDNS0_DAU) unpack(b []byte) error { e.AlgCode = b; return nil }
 
 func (e *EDNS0_DAU) String() string {
 	s := ""
-	for i := 0; i < len(e.AlgCode); i++ {
-		if a, ok := AlgorithmToString[e.AlgCode[i]]; ok {
+	for _, alg := range e.AlgCode {
+		if a, ok := AlgorithmToString[alg]; ok {
 			s += " " + a
 		} else {
-			s += " " + strconv.Itoa(int(e.AlgCode[i]))
+			s += " " + strconv.Itoa(int(alg))
 		}
 	}
 	return s
 }
+func (e *EDNS0_DAU) copy() EDNS0 { return &EDNS0_DAU{e.Code, e.AlgCode} }
 
+// EDNS0_DHU implements the EDNS0 "DS Hash Understood" option. See RFC 6975.
 type EDNS0_DHU struct {
 	Code    uint16 // Always EDNS0DHU
 	AlgCode []uint8
 }
 
+// Option implements the EDNS0 interface.
 func (e *EDNS0_DHU) Option() uint16        { return EDNS0DHU }
 func (e *EDNS0_DHU) pack() ([]byte, error) { return e.AlgCode, nil }
 func (e *EDNS0_DHU) unpack(b []byte) error { e.AlgCode = b; return nil }
 
 func (e *EDNS0_DHU) String() string {
 	s := ""
-	for i := 0; i < len(e.AlgCode); i++ {
-		if a, ok := HashToString[e.AlgCode[i]]; ok {
+	for _, alg := range e.AlgCode {
+		if a, ok := HashToString[alg]; ok {
 			s += " " + a
 		} else {
-			s += " " + strconv.Itoa(int(e.AlgCode[i]))
+			s += " " + strconv.Itoa(int(alg))
 		}
 	}
 	return s
 }
+func (e *EDNS0_DHU) copy() EDNS0 { return &EDNS0_DHU{e.Code, e.AlgCode} }
 
+// EDNS0_N3U implements the EDNS0 "NSEC3 Hash Understood" option. See RFC 6975.
 type EDNS0_N3U struct {
 	Code    uint16 // Always EDNS0N3U
 	AlgCode []uint8
 }
 
+// Option implements the EDNS0 interface.
 func (e *EDNS0_N3U) Option() uint16        { return EDNS0N3U }
 func (e *EDNS0_N3U) pack() ([]byte, error) { return e.AlgCode, nil }
 func (e *EDNS0_N3U) unpack(b []byte) error { e.AlgCode = b; return nil }
@@ -437,41 +569,58 @@ func (e *EDNS0_N3U) unpack(b []byte) error { e.AlgCode = b; return nil }
 func (e *EDNS0_N3U) String() string {
 	// Re-use the hash map
 	s := ""
-	for i := 0; i < len(e.AlgCode); i++ {
-		if a, ok := HashToString[e.AlgCode[i]]; ok {
+	for _, alg := range e.AlgCode {
+		if a, ok := HashToString[alg]; ok {
 			s += " " + a
 		} else {
-			s += " " + strconv.Itoa(int(e.AlgCode[i]))
+			s += " " + strconv.Itoa(int(alg))
 		}
 	}
 	return s
 }
+func (e *EDNS0_N3U) copy() EDNS0 { return &EDNS0_N3U{e.Code, e.AlgCode} }
 
+// EDNS0_EXPIRE implements the EDNS0 option as described in RFC 7314.
 type EDNS0_EXPIRE struct {
 	Code   uint16 // Always EDNS0EXPIRE
 	Expire uint32
+	Empty  bool // Empty is used to signal an empty Expire option in a backwards compatible way, it's not used on the wire.
 }
 
+// Option implements the EDNS0 interface.
 func (e *EDNS0_EXPIRE) Option() uint16 { return EDNS0EXPIRE }
-func (e *EDNS0_EXPIRE) String() string { return strconv.FormatUint(uint64(e.Expire), 10) }
+func (e *EDNS0_EXPIRE) copy() EDNS0    { return &EDNS0_EXPIRE{e.Code, e.Expire, e.Empty} }
 
 func (e *EDNS0_EXPIRE) pack() ([]byte, error) {
+	if e.Empty {
+		return []byte{}, nil
+	}
 	b := make([]byte, 4)
-	b[0] = byte(e.Expire >> 24)
-	b[1] = byte(e.Expire >> 16)
-	b[2] = byte(e.Expire >> 8)
-	b[3] = byte(e.Expire)
+	binary.BigEndian.PutUint32(b, e.Expire)
 	return b, nil
 }
 
 func (e *EDNS0_EXPIRE) unpack(b []byte) error {
+	if len(b) == 0 {
+		// zero-length EXPIRE query, see RFC 7314 Section 2
+		e.Empty = true
+		return nil
+	}
 	if len(b) < 4 {
 		return ErrBuf
 	}
-	e.Expire = uint32(b[0])<<24 | uint32(b[1])<<16 | uint32(b[2])<<8 | uint32(b[3])
+	e.Expire = binary.BigEndian.Uint32(b)
+	e.Empty = false
 	return nil
 }
 
+func (e *EDNS0_EXPIRE) String() (s string) {
+	if e.Empty {
+		return ""
+	}
+	return strconv.FormatUint(uint64(e.Expire), 10)
+}
+
 // The EDNS0_LOCAL option is used for local/experimental purposes. The option
 // code is recommended to be within the range [EDNS0LOCALSTART, EDNS0LOCALEND]
 // (RFC6891), although any unassigned code can actually be used.  The content of
@@ -490,10 +639,16 @@ type EDNS0_LOCAL struct {
 	Data []byte
 }
 
+// Option implements the EDNS0 interface.
 func (e *EDNS0_LOCAL) Option() uint16 { return e.Code }
 func (e *EDNS0_LOCAL) String() string {
 	return strconv.FormatInt(int64(e.Code), 10) + ":0x" + hex.EncodeToString(e.Data)
 }
+func (e *EDNS0_LOCAL) copy() EDNS0 {
+	b := make([]byte, len(e.Data))
+	copy(b, e.Data)
+	return &EDNS0_LOCAL{e.Code, b}
+}
 
 func (e *EDNS0_LOCAL) pack() ([]byte, error) {
 	b := make([]byte, len(e.Data))
@@ -512,3 +667,185 @@ func (e *EDNS0_LOCAL) unpack(b []byte) error {
 	}
 	return nil
 }
+
+// EDNS0_TCP_KEEPALIVE is an EDNS0 option that instructs the server to keep
+// the TCP connection alive. See RFC 7828.
+type EDNS0_TCP_KEEPALIVE struct {
+	Code uint16 // Always EDNSTCPKEEPALIVE
+
+	// Timeout is an idle timeout value for the TCP connection, specified in
+	// units of 100 milliseconds, encoded in network byte order. If set to 0,
+	// pack will return a nil slice.
+	Timeout uint16
+
+	// Length is the option's length.
+	// Deprecated: this field is deprecated and is always equal to 0.
+	Length uint16
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_TCP_KEEPALIVE) Option() uint16 { return EDNS0TCPKEEPALIVE }
+
+func (e *EDNS0_TCP_KEEPALIVE) pack() ([]byte, error) {
+	if e.Timeout > 0 {
+		b := make([]byte, 2)
+		binary.BigEndian.PutUint16(b, e.Timeout)
+		return b, nil
+	}
+	return nil, nil
+}
+
+func (e *EDNS0_TCP_KEEPALIVE) unpack(b []byte) error {
+	switch len(b) {
+	case 0:
+	case 2:
+		e.Timeout = binary.BigEndian.Uint16(b)
+	default:
+		return fmt.Errorf("dns: length mismatch, want 0/2 but got %d", len(b))
+	}
+	return nil
+}
+
+func (e *EDNS0_TCP_KEEPALIVE) String() string {
+	s := "use tcp keep-alive"
+	if e.Timeout == 0 {
+		s += ", timeout omitted"
+	} else {
+		s += fmt.Sprintf(", timeout %dms", e.Timeout*100)
+	}
+	return s
+}
+
+func (e *EDNS0_TCP_KEEPALIVE) copy() EDNS0 { return &EDNS0_TCP_KEEPALIVE{e.Code, e.Timeout, e.Length} }
+
+// EDNS0_PADDING option is used to add padding to a request/response. The default
+// value of padding SHOULD be 0x0 but other values MAY be used, for instance if
+// compression is applied before encryption which may break signatures.
+type EDNS0_PADDING struct {
+	Padding []byte
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_PADDING) Option() uint16        { return EDNS0PADDING }
+func (e *EDNS0_PADDING) pack() ([]byte, error) { return e.Padding, nil }
+func (e *EDNS0_PADDING) unpack(b []byte) error { e.Padding = b; return nil }
+func (e *EDNS0_PADDING) String() string        { return fmt.Sprintf("%0X", e.Padding) }
+func (e *EDNS0_PADDING) copy() EDNS0 {
+	b := make([]byte, len(e.Padding))
+	copy(b, e.Padding)
+	return &EDNS0_PADDING{b}
+}
+
+// Extended DNS Error Codes (RFC 8914).
+const (
+	ExtendedErrorCodeOther uint16 = iota
+	ExtendedErrorCodeUnsupportedDNSKEYAlgorithm
+	ExtendedErrorCodeUnsupportedDSDigestType
+	ExtendedErrorCodeStaleAnswer
+	ExtendedErrorCodeForgedAnswer
+	ExtendedErrorCodeDNSSECIndeterminate
+	ExtendedErrorCodeDNSBogus
+	ExtendedErrorCodeSignatureExpired
+	ExtendedErrorCodeSignatureNotYetValid
+	ExtendedErrorCodeDNSKEYMissing
+	ExtendedErrorCodeRRSIGsMissing
+	ExtendedErrorCodeNoZoneKeyBitSet
+	ExtendedErrorCodeNSECMissing
+	ExtendedErrorCodeCachedError
+	ExtendedErrorCodeNotReady
+	ExtendedErrorCodeBlocked
+	ExtendedErrorCodeCensored
+	ExtendedErrorCodeFiltered
+	ExtendedErrorCodeProhibited
+	ExtendedErrorCodeStaleNXDOMAINAnswer
+	ExtendedErrorCodeNotAuthoritative
+	ExtendedErrorCodeNotSupported
+	ExtendedErrorCodeNoReachableAuthority
+	ExtendedErrorCodeNetworkError
+	ExtendedErrorCodeInvalidData
+)
+
+// ExtendedErrorCodeToString maps extended error info codes to a human readable
+// description.
+var ExtendedErrorCodeToString = map[uint16]string{
+	ExtendedErrorCodeOther:                      "Other",
+	ExtendedErrorCodeUnsupportedDNSKEYAlgorithm: "Unsupported DNSKEY Algorithm",
+	ExtendedErrorCodeUnsupportedDSDigestType:    "Unsupported DS Digest Type",
+	ExtendedErrorCodeStaleAnswer:                "Stale Answer",
+	ExtendedErrorCodeForgedAnswer:               "Forged Answer",
+	ExtendedErrorCodeDNSSECIndeterminate:        "DNSSEC Indeterminate",
+	ExtendedErrorCodeDNSBogus:                   "DNSSEC Bogus",
+	ExtendedErrorCodeSignatureExpired:           "Signature Expired",
+	ExtendedErrorCodeSignatureNotYetValid:       "Signature Not Yet Valid",
+	ExtendedErrorCodeDNSKEYMissing:              "DNSKEY Missing",
+	ExtendedErrorCodeRRSIGsMissing:              "RRSIGs Missing",
+	ExtendedErrorCodeNoZoneKeyBitSet:            "No Zone Key Bit Set",
+	ExtendedErrorCodeNSECMissing:                "NSEC Missing",
+	ExtendedErrorCodeCachedError:                "Cached Error",
+	ExtendedErrorCodeNotReady:                   "Not Ready",
+	ExtendedErrorCodeBlocked:                    "Blocked",
+	ExtendedErrorCodeCensored:                   "Censored",
+	ExtendedErrorCodeFiltered:                   "Filtered",
+	ExtendedErrorCodeProhibited:                 "Prohibited",
+	ExtendedErrorCodeStaleNXDOMAINAnswer:        "Stale NXDOMAIN Answer",
+	ExtendedErrorCodeNotAuthoritative:           "Not Authoritative",
+	ExtendedErrorCodeNotSupported:               "Not Supported",
+	ExtendedErrorCodeNoReachableAuthority:       "No Reachable Authority",
+	ExtendedErrorCodeNetworkError:               "Network Error",
+	ExtendedErrorCodeInvalidData:                "Invalid Data",
+}
+
+// StringToExtendedErrorCode is a map from human readable descriptions to
+// extended error info codes.
+var StringToExtendedErrorCode = reverseInt16(ExtendedErrorCodeToString)
+
+// EDNS0_EDE option is used to return additional information about the cause of
+// DNS errors.
+type EDNS0_EDE struct {
+	InfoCode  uint16
+	ExtraText string
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_EDE) Option() uint16 { return EDNS0EDE }
+func (e *EDNS0_EDE) copy() EDNS0    { return &EDNS0_EDE{e.InfoCode, e.ExtraText} }
+
+func (e *EDNS0_EDE) String() string {
+	info := strconv.FormatUint(uint64(e.InfoCode), 10)
+	if s, ok := ExtendedErrorCodeToString[e.InfoCode]; ok {
+		info += fmt.Sprintf(" (%s)", s)
+	}
+	return fmt.Sprintf("%s: (%s)", info, e.ExtraText)
+}
+
+func (e *EDNS0_EDE) pack() ([]byte, error) {
+	b := make([]byte, 2+len(e.ExtraText))
+	binary.BigEndian.PutUint16(b[0:], e.InfoCode)
+	copy(b[2:], []byte(e.ExtraText))
+	return b, nil
+}
+
+func (e *EDNS0_EDE) unpack(b []byte) error {
+	if len(b) < 2 {
+		return ErrBuf
+	}
+	e.InfoCode = binary.BigEndian.Uint16(b[0:])
+	e.ExtraText = string(b[2:])
+	return nil
+}
+
+// The EDNS0_ESU option for ENUM Source-URI Extension
+type EDNS0_ESU struct {
+	Code uint16
+	Uri  string
+}
+
+// Option implements the EDNS0 interface.
+func (e *EDNS0_ESU) Option() uint16        { return EDNS0ESU }
+func (e *EDNS0_ESU) String() string        { return e.Uri }
+func (e *EDNS0_ESU) copy() EDNS0           { return &EDNS0_ESU{e.Code, e.Uri} }
+func (e *EDNS0_ESU) pack() ([]byte, error) { return []byte(e.Uri), nil }
+func (e *EDNS0_ESU) unpack(b []byte) error {
+	e.Uri = string(b)
+	return nil
+}